Technical annex – Assessing change in England, Scotland and UK Butterfly Indicators Tom Brereton, Butterfly Conservation David Roy, Centre for Ecology and Hydrology May 2009 update Introduction Long time series of species abundance data such as those collected through the UK Butterfly Monitoring Scheme and used to compile UK and England Biodiversity Strategy (EBS) Butterfly Indicators can not always be summarised adequately by linear trend lines. These long time series may show alternating periods of increase and decrease, and it can be difficult to separate patterns of genuine change from annual fluctuations. Consequently, methods that model smoothed trend lines through abundance data are becoming increasingly popular. An extension of the linear trend approach is the application of a smoothing technique that describes the pattern by assigning a trend level (= modelled abundance) to each year in the time series (similar to a moving average). There are several smoothing methods available such as polynomial regression, splines and Loess estimators. These models may be summarised as ‘flexible trend models’. The most popular flexible trend models for the analysis of wildlife populations are General Additive Models (GAMs) and these, for example, are used to produce the EBS Bird Indicators. However, GAMs do not present the complete time series and do not account for serial correlation which limits their applicability to butterfly data. Another flexible trend method from the class of structural time series analysis has recently been developed (Visser, 2005) and applied to European birds (Gregory et al. 2007) and European butterflies (Brereton et al. in press) using TrendSpotter software (Visser, 2004). This is the approach used to describe and assess changes in the UK and EBS Butterfly Indicator updates published in April 2008. Unlike the GAM approach, the confidence interval of the trend line is not calculated by a bootstrapping method but by application of a time series analysis and the Kalman filter (Visser 2004). This approach uses one observation per time point (e.g. year or month) and therefore the uncertainty in the estimate of yearly index values (e.g. confidence intervals around each year index) is modelled indirectly in the annual fluctuations. The main advantage of the TrendSpotter analysis however is the calculation of confidence intervals for the differences between the trend level of the last year and each of the preceding years, taking into account serial correlation which is unique for flexible trend methods. This allows short-term trends to be usefully assessed. TrendSpotter estimates smoothed population numbers µ1, µ2, . . . , µt, . . . , µN, for a time series with N equidistant measurements over time (y1, y2, . . . , yt, . . . , yN). The expectations of these smoothed population numbers are denoted as m 1, m2, . . . , mt, . . . , mN. TrendSpotter also estimates the standard deviations of the smoothed population numbers: SD1, SD2, . . . , SDt, . . . , SDN. Finally, it estimates the standard deviations of the differences µN–µt, denoted here as SDN–t. The estimation of confidence intervals is based on the deviations of time point values from the smoothed line. This emphasises temporal variation as the main source of error, although measurement errors and errors due to imputation are implicitly incorporated in the yearly measurements. In TrendSpotter, the flexibility of a trend is set by the value of a standard deviation of a noise process. This standard deviation (parameter) can be chosen by hand, or can be optimised by maximum likelihood optimisation (the default choice). If the parameter is set to zero, the estimated trend equals the well-known regression trend line (straight line). If the parameter is set to a very large number, the trend will go through all measurements y1, y2, . . . , yt, . . . , yN. All values for mI, SDI, and SDN–t are estimated by use of the Kalman filter. This filter is attractive, because it gives estimates with optimal statistical properties. Although normally distributed residuals are not a necessary condition for the proper use of the Kalman filter, it still is a desirable property. For example, all confidence limits assessed by ±1.96 X standard error can be interpreted as 95% confidence limits. Normality of residuals can be tested by a so-called normality plot. In TrendSpotter, a statistical test is performed to compare the difference in the Index in the latest year versus other years in the series. Yearly Change Rates and confidence intervals produced in the TrendSpotter output are used to classify the trends per year. The trend classification applied (see Soldaat et al. 2007) is given in Table 1. Table 1: Classification of trends on the basis of the 95% confidence intervals of the yearly change rate in TrendSpotter smoothed indices. CL = confidence limit; CI = confidence interval (see Soldaat et al. for explanation). trend class criteria description strong increase lower CL > 1,05 > 5% increase / year (≈ doubling in 15 years) moderate increase 1,00 < lower CL ≤ 1,05 increase, but unsure whether > 5% / year stable confidence interval contains 1,00 AND lower CL ≥ 0,95 AND upper CL ≤ 1,05 population changes less than 5% / year moderate decline 0,95 ≤ upper CL < 1,00 decrease, but unsure whether > 5% / year steep decline upper CL < 0,95 > 5% decrease / year (≈ halving in 15 years) uncertain confidence interval contains 1,00 AND (lower CL < 0,95 OR upper CL > 1,05) CI too large for reliable trend classification In summary structural time series models are essentially regression models in which the explanatory variables are functions of time and the parameters are time-varying. The Kalman filter is an efficient recursive filter that estimates the state of a dynamic system from a series of incomplete and noisy measurements. For mathematical details about structural time-series analysis and the Kalman filter please refer to Harvey (1989). TrendSpotter is currently considered the best-available technique in the assessment of Governmental Butterfly Indicators. Regular reviews of methods to assess changes in butterfly indicators are needed however; techniques to model trends are an active area of statistical development. Example of TrendSpotter outputs For the EBS Populations of Butterflies Indicator H1(b) generalist and specialist indices and the corresponding smoothed trend for the period 1976-2006 are given in Figure 1. Tests for changes in smoothed indices between 2006 and previous years are given in Table 2. Plots of the test results comparing years are given in Figure 2. Table 2: Indices and trend classification for specialist and generalist species of the EBS Populations of Butterflies Indicator (H1b) Specialist species Year Index 1976 100 1977 58 1978 47 1979 34 1980 33 1981 18 1982 28 1983 1984 1985 Smoothed Index Generalist species Trend class Index Smoothed Index Trend class 74.79 moderate decline 100 78.45 stable 63.47 moderate decline 48 80.32 stable 53.06 moderate decline 76 82.22 stable 44.26 moderate decline 88 84.14 stable 37.57 stable 74 86.05 stable 33.11 stable 60 87.95 stable 30.85 stable 115 89.78 stable 28 30.22 stable 106 91.50 stable 46 30.54 stable 140 93.06 stable 35 31.05 stable 86 94.45 stable 1986 33 31.57 stable 81 95.71 stable 1987 36 32.01 stable 66 96.87 stable 1988 29 32.38 stable 70 97.95 stable 1989 31 32.80 stable 109 98.92 stable 1990 34 33.28 stable 111 99.72 stable 1991 30 33.77 stable 123 100.30 stable 1992 41 34.23 stable 140 100.63 stable 1993 30 34.51 stable 76 100.70 stable 1994 33 34.68 stable 83 100.56 stable 1995 38 34.65 stable 109 100.22 stable 1996 37 34.29 stable 118 99.68 stable 1997 42 33.57 stable 126 98.93 stable 1998 29 32.57 stable 91 98.00 stable 1999 29 31.65 uncertain 82 96.95 stable 2000 29 31.06 uncertain 87 95.84 stable 2001 26 30.96 uncertain 80 94.70 stable 2002 26 31.42 uncertain 83 93.54 stable 2003 35 32.34 uncertain 102 92.38 stable 2004 38 33.44 uncertain 97 91.20 stable 2005 37 34.52 uncertain 91 89.99 uncertain 2006 34 35.54 81 88.78 140 120 120 Combined Index Combined Index 100 80 60 40 20 100 80 60 40 20 0 1975 1985 1995 0 1975 2005 1985 1995 Year Year Specialists Generalists Figure 1: Time series analysis of the EBS Populations of Butterflies Indicator (H1b). The black dots indicate the observed index; the black line is the smoothed trend line estimated by TrendSpotter. The dashed black lines indicate the upper and lower boundary of the 95% confidence limits of the smoothed trend line. 20 Trend difference (plus 95% CL of test tesults) 10 0 1975 1980 1985 1990 1995 2000 2005 -10 -20 -30 -40 -50 Year Figure 2: Test result for the EBS Populations of Butterflies Indicator (H1b) comparing the difference in the all species index in the latest year with previous years in the series. The solid dots represent the difference in previous year index values compared with the latest year, whilst dashed black lines indicate the upper and lower boundary of the 95% confidence limits of the test results. Previous year indices are different to the latest year, if both 95% confidence interval lines do not cross 0. In this example, 1976-1978 are different (significantly lower than) to 2006. 2005 Trend assessment based on the TrendSpotter approach suggest that the 2006 specialist index was significantly lower than over the period 1976-1978, though the trend since 2000 is uncertain. No significant change has occurred in the generalist butterfly index, which is classed as stable over all years except 2005, where there is uncertainty. References Brereton, T, van Swaay C and van Strien A (in press) Developing a butterfly indicator to assess changes in Europe’s biodiversity. Conference Proceedings of the European Bird Census Council Bird Numbers 2007 Conference. Chiavenna, Italy. Gregory, RD, Vorisek, P, van Strien AJ, Gmelig Meyling AW, Jiguet F, Fornasari, L, Jiri R, Chylarecki P, Burfield, IJ (2007) Population trends of widespread woodland birds in Europe. Ibis: 149 (Suppl. 2), 78–97. Harvey AC (1989) Forecasting structural time series models and the Kalman filter. Cambridge University Press, London. Soldaat, LL, Visser, P, van Roomen, M, van Strien, A (2007) Smoothing and trend detection in waterbird monitoring data using structural time-series analysis and the Kalman filter. Journal of Ornithology. Vol. 148 suppl. 2. Dec. 2007. Visser H (2004) Estimation and detection of flexible trends. Atm Environment 38: 4135-4145. Visser H (2005) The significance of climate change in the Netherlands. An analysis of historical and future trends (1901-2020). MNP report 550002007. Appendix Trend results for England, Scotland and UK Butterfly Indicators 1976-2007 Indicator Year Index Smoothed Index (SI) SI Lower CL. SI Upper CL. Trend Difference (TD) TD Lower CL. TD Upper CL. TREND CLASSIFICATION England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Specialists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 100 51.1 40.8 34.9 35.8 18.9 29.6 29.7 48.4 35.7 34.6 37.5 31 33.5 39.5 30.3 44 32.2 37.1 41.9 38.4 44 29.6 30.3 29.1 29.6 28.3 37.2 38.9 38.1 36.8 23.9 100 46 74.1 88.1 74.1 62.9 112 100 129 79.2 75.1 63.5 66 100 100 110 127 69.5 75.8 97.7 104 113 82 75.1 79 70.9 69.72 60.07 51.27 43.93 38.35 34.60 32.65 32.06 32.31 32.80 33.38 33.98 34.56 35.18 35.81 36.36 36.84 37.12 37.23 37.09 36.62 35.84 34.86 33.98 33.38 33.13 33.19 33.39 33.47 33.25 32.69 31.92 79.09 80.25 81.44 82.64 83.83 85.00 86.11 87.12 88.01 88.78 89.45 90.05 90.60 91.06 91.40 91.59 91.60 91.43 91.10 90.62 89.99 89.20 88.26 87.23 86.12 84.95 63.37 55.15 47.13 40.08 34.57 30.82 28.87 28.30 28.57 29.07 29.66 30.27 30.85 31.48 32.10 32.65 33.14 33.41 33.53 33.39 32.91 32.12 31.13 30.23 29.62 29.36 29.41 29.61 29.62 29.09 27.75 25.51 62.91 65.97 68.73 71.19 73.32 75.16 76.72 78.00 79.04 79.87 80.55 81.15 81.67 82.11 82.44 82.62 82.63 82.47 82.15 81.69 81.08 80.30 79.35 78.25 76.99 75.55 76.07 64.98 55.42 47.78 42.13 38.37 36.42 35.83 36.06 36.53 37.10 37.69 38.26 38.88 39.51 40.06 40.55 40.82 40.93 40.80 40.33 39.56 38.58 37.72 37.15 36.91 36.96 37.18 37.33 37.40 37.64 38.33 95.26 94.54 94.16 94.10 94.34 94.83 95.50 96.24 96.99 97.69 98.35 98.96 99.52 100.01 100.36 100.56 100.57 100.39 100.04 99.55 98.89 98.09 97.18 96.20 95.24 94.35 -37.80 -28.15 -19.36 -12.01 -6.44 -2.68 -0.73 -0.15 -0.40 -0.89 -1.46 -2.06 -2.64 -3.26 -3.89 -4.44 -4.93 -5.20 -5.31 -5.18 -4.70 -3.92 -2.94 -2.06 -1.47 -1.22 -1.27 -1.48 -1.55 -1.33 -0.78 0 -2.09 -3.26 -4.45 -5.65 -6.84 -8.00 -9.11 -10.12 -11.02 -11.78 -12.45 -13.06 -13.60 -14.06 -14.40 -14.59 -14.60 -14.43 -14.10 -13.62 -12.99 -12.20 -11.27 -10.23 -9.12 -7.95 -46.83 -36.23 -26.99 -19.49 -13.88 -10.12 -8.17 -7.57 -7.81 -8.29 -8.86 -9.45 -10.03 -10.65 -11.29 -11.85 -12.36 -12.66 -12.82 -12.74 -12.33 -11.62 -10.69 -9.84 -9.20 -8.80 -8.53 -8.17 -7.34 -5.77 -3.33 0 -25.01 -24.97 -25.25 -25.80 -26.56 -27.46 -28.44 -29.41 -30.32 -31.13 -31.86 -32.51 -33.08 -33.54 -33.85 -33.96 -33.83 -33.46 -32.84 -31.98 -30.86 -29.45 -27.76 -25.79 -23.57 -21.09 -28.78 -20.07 -11.72 -4.54 1.01 4.76 6.71 7.28 7.02 6.52 5.93 5.33 4.75 4.13 3.51 2.97 2.51 2.26 2.19 2.39 2.93 3.77 4.81 5.71 6.27 6.36 5.99 5.22 4.23 3.11 1.78 0 20.84 18.46 16.36 14.51 12.89 11.47 10.22 9.17 8.29 7.57 6.95 6.39 5.88 5.42 5.05 4.78 4.63 4.60 4.65 4.74 4.89 5.06 5.23 5.34 5.34 5.18 moderate decline uncertain moderate decline moderate decline stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable uncertain uncertain uncertain uncertain uncertain uncertain stable uncertain stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable Indicator Year Index Smoothed Index (SI) SI Lower CL. SI Upper CL. Trend Difference (TD) TD Lower CL. TD Upper CL. TREND CLASSIFICATION England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-Generalists England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-All species England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Specialists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists 2002 2003 2004 2005 2006 2007 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1990 1991 1992 1993 1994 77.4 93.5 92.4 85.3 78.5 58 100 48.5 62 65.3 60.2 41 68.8 64.5 93.3 62.5 59.8 57.1 53 68.3 74.1 68.3 87.9 55.5 62.3 75.1 74.4 83.1 57.9 56.1 56.3 53.8 55 69.3 70.6 66.9 63.1 43.7 100 64.5 100 83.9 90.3 105 94.6 98.4 73.1 82.6 77.4 72.1 64.1 87.5 77.2 92.6 75.1 47.4 100 121 126 73.7 87.9 83.74 82.49 81.18 79.82 78.42 77.00 68.12 67.92 67.71 67.51 67.30 67.10 66.89 66.69 66.48 66.28 66.07 65.87 65.66 65.46 65.26 65.05 64.85 64.64 64.44 64.23 64.03 63.82 63.62 63.41 63.21 63.00 62.80 62.59 62.39 62 62 62 94.69 93.26 91.83 90.40 88.98 87.55 86.12 84.69 83.26 81.83 80.41 78.98 77.55 76.12 74.69 73.27 71.84 70.41 109.30 108.45 107.58 106.69 105.83 73.89 71.96 69.69 67.07 64.09 60.77 61.16 61.28 61.40 61.51 61.61 61.70 61.78 61.84 61.89 61.92 61.92 61.90 61.85 61.76 61.64 61.48 61.27 61.02 60.74 60.41 60.06 59.67 59.25 58.81 58.36 57.88 57.39 56.89 56.38 56 55 55 83.02 82.58 82.09 81.55 80.93 80.21 79.37 78.36 77.15 75.71 74.07 72.22 70.20 68.06 65.82 63.50 61.13 58.72 96.66 97.56 98.06 98.16 97.97 93.59 93.01 92.66 92.56 92.75 93.22 75.09 74.55 74.03 73.51 73.00 72.50 72.01 71.54 71.08 70.64 70.23 69.84 69.48 69.16 68.87 68.62 68.42 68.26 68.13 68.05 68.00 67.98 67.98 68.01 68.06 68.12 68.20 68.30 68.40 69 69 69 106.35 103.94 101.57 99.26 97.02 94.88 92.87 91.02 89.38 87.95 86.75 85.74 84.90 84.18 83.57 83.03 82.54 82.09 121.94 119.34 117.10 115.21 113.69 -6.74 -5.49 -4.18 -2.82 -1.42 0 -6.35 -6.14 -5.94 -5.73 -5.53 -5.32 -5.12 -4.91 -4.71 -4.50 -4.30 -4.09 -3.89 -3.69 -3.48 -3.28 -3.07 -2.87 -2.66 -2.46 -2.25 -2.05 -1.84 -1.64 -1.43 -1.23 -1.02 -0.82 -0.61 -0.41 -0.21 0 -24.28 -22.85 -21.42 -19.99 -18.57 -17.14 -15.71 -14.28 -12.85 -11.43 -10.00 -8.57 -7.14 -5.71 -4.28 -2.86 -1.43 0.00 -23.16 -22.30 -21.43 -20.54 -19.69 -18.34 -15.30 -11.95 -8.29 -4.31 0 -18.32 -17.73 -17.14 -16.55 -15.96 -15.36 -14.77 -14.18 -13.59 -13.00 -12.41 -11.82 -11.23 -10.64 -10.05 -9.46 -8.86 -8.27 -7.68 -7.09 -6.50 -5.91 -5.32 -4.73 -4.14 -3.54 -2.95 -2.36 -1.77 -1.18 -0.59 0 -44.20 -41.60 -39.00 -36.40 -33.80 -31.20 -28.60 -26.00 -23.40 -20.80 -18.20 -15.60 -13.00 -10.40 -7.80 -5.20 -2.60 0.00 -42.47 -40.37 -38.55 -36.96 -35.56 4.85 4.32 3.59 2.65 1.47 0 5.63 5.45 5.26 5.08 4.90 4.72 4.54 4.36 4.17 3.99 3.81 3.63 3.45 3.27 3.09 2.90 2.72 2.54 2.36 2.18 2.00 1.82 1.63 1.45 1.27 1.09 0.91 0.73 0.54 0.36 0.18 0 -4.36 -4.10 -3.84 -3.59 -3.33 -3.08 -2.82 -2.56 -2.31 -2.05 -1.79 -1.54 -1.28 -1.02 -0.77 -0.51 -0.26 0.00 -3.84 -4.23 -4.31 -4.13 -3.81 stable stable uncertain uncertain uncertain stable uncertain stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable moderate decline uncertain moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline uncertain moderate decline moderate decline moderate decline Indicator Year Index Smoothed Index (SI) SI Lower CL. SI Upper CL. Trend Difference (TD) TD Lower CL. TD Upper CL. TREND CLASSIFICATION England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland Generalists England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Farmland All species England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Specialists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 107 116 133 100 90.5 98.6 88.3 88.7 113 101 95.5 93.1 63.1 100 89.3 112 78.8 89.3 107 105 114 85.9 86.7 87.5 79.9 75.6 99.7 88.9 94.1 83.9 54.9 100 82.7 99.3 55.5 60.9 76.9 76.3 99.7 55.2 50.9 51.1 71.2 59.2 79.8 84.9 74.3 36.9 26.8 100 91.2 111 56.7 63.1 82.9 87.7 85.3 56.8 53 52.1 47.4 104.98 104.07 103.04 101.83 100.50 99.07 97.55 95.93 94.21 92.36 90.37 88.29 86.15 101.22 100.13 99.04 97.94 96.83 95.69 94.50 93.26 91.94 90.58 89.18 87.75 86.28 84.78 83.24 81.66 80.04 78.39 98.35 89.51 82.42 68.34 66.03 73.33 79.71 80.45 65.26 55.27 55.21 62.64 68.43 77.44 79.44 68.07 45.88 25.62 99.25 96.28 99.56 65.33 64.21 80.57 87.67 82.03 60.55 52.74 50.65 48.93 97.52 96.82 95.88 94.72 93.39 91.92 90.29 88.46 86.34 83.81 80.82 77.36 73.45 89.37 89.60 89.63 89.46 89.08 88.49 87.69 86.68 85.49 84.13 82.61 80.93 79.07 77.02 74.74 72.23 69.48 66.52 82.46 77.18 70.13 56.15 53.89 61.20 67.58 68.32 53.13 43.14 43.08 50.51 56.30 65.30 67.24 55.74 33.55 9.25 94.87 92.31 95.62 61.39 60.27 76.63 83.73 78.09 56.61 48.80 46.71 44.99 112.45 111.33 110.19 108.95 107.62 106.23 104.80 103.40 102.09 100.90 99.92 99.21 98.84 113.06 110.66 108.44 106.42 104.58 102.89 101.31 99.83 98.40 97.04 95.76 94.57 93.49 92.55 91.74 91.08 90.59 90.27 114.24 101.83 94.71 80.52 78.16 85.46 91.84 92.58 77.39 67.40 67.34 74.77 80.56 89.57 91.63 80.39 58.21 41.99 103.63 100.25 103.51 69.27 68.15 84.51 91.61 85.97 64.49 56.68 54.59 52.87 -18.84 -17.93 -16.89 -15.69 -14.36 -12.93 -11.40 -9.79 -8.07 -6.21 -4.22 -2.14 0.00 -22.82 -21.74 -20.65 -19.54 -18.43 -17.29 -16.11 -14.86 -13.55 -12.19 -10.79 -9.36 -7.89 -6.39 -4.85 -3.26 -1.64 0.00 -72.73 -63.89 -56.80 -42.71 -40.41 -47.71 -54.09 -54.83 -39.64 -29.65 -29.59 -37.02 -42.81 -51.82 -53.82 -42.44 -20.26 0 -64.39 -61.42 -64.70 -30.47 -29.35 -45.71 -52.81 -47.18 -25.69 -17.88 -15.79 -14.07 -34.28 -32.96 -31.50 -29.79 -27.83 -25.61 -23.10 -20.27 -17.08 -13.45 -9.39 -4.91 0.00 -41.95 -39.70 -37.58 -35.55 -33.60 -31.69 -29.75 -27.74 -25.65 -23.44 -21.11 -18.64 -16.01 -13.22 -10.22 -7.02 -3.62 0.00 -95.54 -84.38 -77.27 -63.12 -60.78 -68.09 -74.47 -75.20 -60.01 -50.01 -49.94 -57.41 -63.35 -72.65 -74.90 -62.77 -36.08 0 -70.68 -67.44 -70.70 -36.46 -35.35 -51.71 -58.80 -53.17 -31.69 -23.88 -21.78 -20.07 -3.39 -2.89 -2.28 -1.59 -0.89 -0.24 0.29 0.69 0.94 1.03 0.94 0.63 0.00 -3.70 -3.77 -3.71 -3.53 -3.26 -2.90 -2.47 -1.98 -1.46 -0.94 -0.47 -0.07 0.24 0.44 0.53 0.50 0.33 0.00 -49.91 -43.39 -36.33 -22.31 -20.03 -27.34 -33.72 -34.46 -19.27 -9.29 -9.23 -16.62 -22.27 -30.98 -32.73 -22.12 -4.44 0 -58.10 -55.41 -58.70 -24.47 -23.36 -39.72 -46.81 -41.18 -19.70 -11.89 -9.79 -8.08 moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline stable stable stable uncertain uncertain uncertain moderate decline uncertain moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline stable stable stable stable stable moderate decline uncertain moderate decline moderate decline moderate decline moderate decline moderate decline steep decline moderate decline moderate decline moderate decline steep decline steep decline steep decline steep decline steep decline steep decline steep decline uncertain steep decline moderate decline moderate decline steep decline steep decline steep decline moderate decline moderate decline moderate decline moderate decline Indicator England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland Generalists England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species England-Woodland All species Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Specialists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Year 2002 2003 2004 2005 2006 2007 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1979 1980 1981 1982 1983 1984 1985 1986 Index Smoothed Index (SI) 55.9 69.9 68.2 59.2 49.6 34.5 100 87.7 106 56.2 62.2 80.5 82.7 90.9 56.2 52.1 51.6 55.9 57.2 73.7 74.4 64.8 44 31.1 100 48.8 37.2 93.1 90.7 109 76.5 33.8 29.3 29.1 30.7 53.4 65.1 74.4 39.2 23.5 47.3 34.9 72.2 48.8 34.9 54 33.5 22.7 27.9 40.3 44.6 47.8 51.8 100 69.9 71.4 145 181 179 101 81.1 56.78 68.08 67.99 59.85 49.14 34.86 98.89 92.93 95.37 64.07 63.12 77.95 84.70 85.09 60.86 51.88 51.43 54.97 59.66 72.03 73.92 63.95 45.56 30.74 76.56 74.08 71.64 69.22 66.78 64.31 61.83 59.40 57.11 55.01 53.13 51.45 49.93 48.55 47.29 46.16 45.17 44.29 43.51 42.80 42.16 41.59 41.11 40.73 40.46 40.29 40.18 40.10 40.04 109.91 111.09 112.26 113.44 114.62 115.80 116.98 118.16 SI Lower CL. SI Upper CL. 52.84 64.14 64.05 55.90 45.15 30.34 93.73 88.24 90.72 59.42 58.48 73.30 80.05 80.44 56.21 47.24 46.78 50.32 55.02 67.38 69.27 59.29 40.85 25.41 61.61 60.94 59.99 58.74 57.17 55.30 53.20 50.98 48.79 46.73 44.85 43.15 41.62 40.22 38.96 37.83 36.85 36.00 35.23 34.52 33.84 33.17 32.47 31.71 30.84 29.79 28.50 26.92 25.05 76.27 79.20 82.10 84.94 87.73 90.46 93.10 95.66 60.71 72.02 71.93 63.80 53.14 39.38 104.06 97.61 100.03 68.72 67.77 82.59 89.34 89.73 65.50 56.53 56.07 59.61 64.31 76.67 78.56 68.60 50.27 36.07 91.51 87.22 83.28 79.69 76.39 73.33 70.46 67.82 65.43 63.29 61.41 59.74 58.25 56.88 55.63 54.49 53.49 52.59 51.80 51.08 50.47 50.02 49.75 49.76 50.09 50.78 51.85 53.28 55.04 143.54 142.97 142.43 141.95 141.51 141.14 140.86 140.66 Trend Difference (TD) -21.92 -33.22 -33.13 -24.99 -14.28 0.00 -68.15 -62.18 -64.63 -33.33 -32.38 -47.20 -53.95 -54.35 -30.12 -21.14 -20.69 -24.22 -28.92 -41.28 -43.17 -33.20 -14.81 0 -36.52 -34.04 -31.59 -29.17 -26.74 -24.27 -21.79 -19.36 -17.07 -14.97 -13.08 -11.40 -9.89 -8.51 -7.25 -6.12 -5.13 -4.25 -3.47 -2.76 -2.11 -1.55 -1.07 -0.69 -0.42 -0.24 -0.13 -0.06 0.00 33.00 31.82 30.65 29.47 28.29 27.11 25.93 24.75 TD Lower CL. TD Upper CL. -27.91 -39.23 -39.18 -31.11 -19.88 0.00 -75.57 -69.28 -71.71 -40.40 -39.45 -54.27 -61.03 -61.42 -37.19 -28.21 -27.76 -31.29 -35.99 -48.36 -50.31 -40.42 -21.41 0 -57.86 -54.23 -50.93 -47.91 -45.08 -42.39 -39.80 -37.34 -35.05 -32.97 -31.11 -29.42 -27.86 -26.39 -24.98 -23.62 -22.31 -21.02 -19.70 -18.31 -16.83 -15.25 -13.56 -11.75 -9.80 -7.69 -5.39 -2.84 0.00 -24.76 -23.88 -22.99 -22.11 -21.22 -20.34 -19.45 -18.57 -15.92 -27.22 -27.08 -18.87 -8.69 0.00 -60.73 -55.09 -57.55 -26.26 -25.31 -40.13 -46.88 -47.27 -23.05 -14.07 -13.62 -17.15 -21.85 -34.20 -36.03 -25.98 -8.22 0 -15.18 -13.85 -12.26 -10.44 -8.39 -6.15 -3.78 -1.38 0.92 3.04 4.94 6.61 8.08 9.37 10.48 11.38 12.06 12.52 12.76 12.80 12.61 12.15 11.42 10.36 8.96 7.21 5.12 2.72 0.00 90.77 87.53 84.28 81.04 77.80 74.56 71.32 68.07 TREND CLASSIFICATION steep decline steep decline steep decline steep decline steep decline steep decline uncertain steep decline moderate decline moderate decline steep decline steep decline steep decline steep decline moderate decline moderate decline steep decline steep decline steep decline steep decline steep decline steep decline moderate decline uncertain moderate decline moderate decline moderate decline moderate decline moderate decline moderate decline stable stable stable stable stable uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain stable uncertain stable stable stable stable stable stable Indicator Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-Generalists Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species Scotland-All species UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists Year 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 Index Smoothed Index (SI) SI Lower CL. SI Upper CL. Trend Difference (TD) TD Lower CL. TD Upper CL. TREND CLASSIFICATION 56.6 68.2 145 149 221 184 92.4 66.3 120 102 151 241 103 87.1 101 100 154 163 150 171 112 100 63.5 59.8 128 125 133 73.7 52.6 43.8 45.1 95.9 107 140 160 74.4 50.8 109 80.5 121 157 82.9 78.3 74.8 74.6 114 116 114 137 99.3 100 58.3 53.3 38.9 37.5 22.3 39.4 38.1 57.4 41.5 38.3 119.34 120.52 121.69 122.87 124.05 125.23 126.41 127.59 128.77 129.94 131.12 132.30 133.48 134.66 135.84 137.02 138.20 139.37 140.55 141.73 142.91 85.52 86.34 87.15 87.97 88.78 89.60 90.42 91.23 92.05 92.86 93.68 94.49 95.31 96.13 96.94 97.76 98.57 99.39 100.21 101.02 101.84 102.65 103.47 104.28 105.10 105.92 106.73 107.55 108.36 72.86 64.49 56.75 50.12 45.00 41.54 39.72 39.08 39.17 39.49 39.98 98.10 100.41 102.56 104.53 106.30 107.84 109.13 110.19 111.00 111.59 111.97 112.17 112.22 112.13 111.93 111.64 111.27 110.84 110.35 109.81 109.24 62.50 64.52 66.51 68.46 70.38 72.26 74.08 75.83 77.51 79.10 80.58 81.94 83.16 84.22 85.12 85.85 86.42 86.83 87.10 87.25 87.29 87.24 87.11 86.92 86.68 86.39 86.06 85.71 85.32 65.89 59.05 52.16 45.89 40.87 37.42 35.60 34.98 35.08 35.42 35.92 140.57 140.62 140.83 141.21 141.81 142.63 143.68 144.99 146.53 148.30 150.28 152.43 154.74 157.19 159.74 162.39 165.12 167.91 170.76 173.65 176.58 108.54 108.15 107.80 107.47 107.18 106.94 106.75 106.63 106.58 106.62 106.77 107.05 107.46 108.03 108.76 109.67 110.73 111.95 113.31 114.80 116.39 118.07 119.83 121.65 123.52 125.44 127.40 129.39 131.40 79.83 69.93 61.33 54.34 49.12 45.65 43.83 43.19 43.25 43.56 44.03 23.57 22.40 21.22 20.04 18.86 17.68 16.50 15.32 14.14 12.97 11.79 10.61 9.43 8.25 7.07 5.89 4.72 3.54 2.36 1.18 0.00 22.84 22.03 21.21 20.40 19.58 18.76 17.95 17.13 16.32 15.50 14.69 13.87 13.05 12.24 11.42 10.61 9.79 8.97 8.16 7.34 6.53 5.71 4.90 4.08 3.26 2.45 1.63 0.82 0.00 -33.83 -25.46 -17.72 -11.09 -5.97 -2.51 -0.69 -0.05 -0.14 -0.46 -0.95 -17.69 -16.80 -15.92 -15.03 -14.15 -13.26 -12.38 -11.50 -10.61 -9.73 -8.84 -7.96 -7.07 -6.19 -5.31 -4.42 -3.54 -2.65 -1.77 -0.88 0.00 -16.68 -16.09 -15.49 -14.90 -14.30 -13.71 -13.11 -12.51 -11.92 -11.32 -10.72 -10.13 -9.53 -8.94 -8.34 -7.75 -7.15 -6.56 -5.96 -5.36 -4.77 -4.17 -3.57 -2.98 -2.38 -1.79 -1.19 -0.60 0.00 -43.73 -34.35 -26.11 -19.29 -14.12 -10.65 -8.83 -8.18 -8.26 -8.57 -9.05 64.83 61.59 58.35 55.11 51.87 48.62 45.38 42.14 38.90 35.66 32.42 29.18 25.93 22.69 19.45 16.21 12.97 9.73 6.48 3.24 0.00 62.37 60.14 57.91 55.69 53.46 51.23 49.00 46.78 44.55 42.32 40.09 37.87 35.64 33.41 31.18 28.96 26.73 24.50 22.27 20.05 17.82 15.59 13.36 11.14 8.91 6.68 4.45 2.23 0.00 -23.93 -16.57 -9.33 -2.89 2.18 5.63 7.45 8.08 7.98 7.64 7.15 stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable uncertain stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable moderate decline uncertain moderate decline moderate decline stable stable stable stable stable stable stable Indicator Year Index Smoothed Index (SI) SI Lower CL. SI Upper CL. Trend Difference (TD) TD Lower CL. TD Upper CL. TREND CLASSIFICATION UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Specialists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-Generalists UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1976 1977 1978 1979 1980 1981 1982 1983 43.8 37.8 40 46.7 37.5 54.2 39.4 45 48.4 44.8 50.5 34.3 35.8 37.1 36.4 32.8 44 44.9 45.6 45.1 30.1 100 49.4 70.9 78.1 69.5 61.3 106 95.2 123 79.4 75.3 65.7 66.3 96.1 93.9 106 120 68.3 76.2 94.4 100 106 78.5 72.1 76.3 69.3 74.9 90.1 88.7 80.9 73.9 54.7 100 52.9 66.5 62.3 57.6 42.3 73.7 68.2 40.60 41.29 42.06 42.84 43.51 44.03 44.24 44.21 43.88 43.23 42.33 41.30 40.42 39.84 39.58 39.61 39.84 39.99 39.93 39.58 39.03 76.18 77.31 78.48 79.67 80.87 82.08 83.24 84.31 85.26 86.07 86.78 87.41 87.97 88.45 88.79 88.97 88.96 88.74 88.35 87.80 87.08 86.19 85.14 83.99 82.75 81.46 80.12 78.73 77.27 75.74 74.17 72.57 69.21 69.08 68.96 68.85 68.75 68.66 68.58 68.51 36.55 37.25 38.03 38.81 39.47 39.99 40.21 40.17 39.84 39.19 38.28 37.23 36.34 35.73 35.46 35.50 35.71 35.76 35.33 34.10 32.00 61.49 64.44 67.10 69.45 71.50 73.28 74.81 76.09 77.13 77.98 78.68 79.30 79.84 80.31 80.65 80.82 80.81 80.59 80.21 79.68 78.97 78.10 77.05 75.86 74.52 73.03 71.32 69.35 67.03 64.33 61.26 57.83 61.59 62.06 62.47 62.83 63.14 63.40 63.61 63.77 44.64 45.33 46.10 46.87 47.54 48.06 48.27 48.24 47.92 47.27 46.39 45.37 44.51 43.94 43.69 43.73 43.96 44.22 44.52 45.05 46.06 90.87 90.18 89.86 89.89 90.24 90.87 91.67 92.54 93.39 94.17 94.87 95.51 96.09 96.58 96.94 97.12 97.11 96.88 96.49 95.92 95.19 94.28 93.24 92.12 90.98 89.90 88.92 88.11 87.51 87.16 87.08 87.32 76.84 76.11 75.46 74.87 74.36 73.92 73.56 73.25 -1.57 -2.26 -3.03 -3.81 -4.48 -5.00 -5.21 -5.18 -4.85 -4.20 -3.31 -2.27 -1.40 -0.81 -0.55 -0.58 -0.81 -0.97 -0.90 -0.55 -9.66 -10.35 -11.13 -11.92 -12.61 -13.16 -13.41 -13.43 -13.17 -12.59 -11.76 -10.78 -9.90 -9.23 -8.77 -8.41 -7.97 -7.11 -5.58 -3.23 6.52 5.83 5.06 4.30 3.65 3.16 2.99 3.08 3.47 4.19 5.15 6.23 7.11 7.61 7.67 7.24 6.35 5.18 3.78 2.13 stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable uncertain uncertain uncertain uncertain -3.61 -4.74 -5.90 -7.09 -8.30 -9.50 -10.67 -11.74 -12.69 -13.50 -14.20 -14.83 -15.39 -15.87 -16.22 -16.40 -16.38 -16.16 -15.78 -15.23 -14.51 -13.61 -12.57 -11.41 -10.18 -8.89 -7.55 -6.16 -4.70 -3.17 -1.60 0 -6.59 -6.46 -6.34 -6.23 -6.13 -6.04 -5.96 -5.89 -24.33 -24.28 -24.58 -25.17 -25.99 -26.98 -28.06 -29.12 -30.10 -30.98 -31.75 -32.45 -33.06 -33.57 -33.93 -34.07 -33.98 -33.63 -33.03 -32.20 -31.09 -29.69 -28.00 -26.04 -23.82 -21.35 -18.60 -15.55 -12.17 -8.45 -4.40 0 -18.36 -17.80 -17.29 -16.84 -16.44 -16.09 -15.79 -15.52 17.11 14.81 12.77 10.98 9.39 7.98 6.72 5.64 4.73 3.98 3.35 2.79 2.28 1.83 1.49 1.28 1.21 1.30 1.48 1.74 2.08 2.46 2.86 3.22 3.47 3.57 3.50 3.24 2.78 2.11 1.20 0 5.19 4.88 4.61 4.39 4.19 4.02 3.87 3.74 stable uncertain stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable uncertain uncertain uncertain uncertain uncertain stable uncertain stable stable stable stable stable stable Indicator Year Index Smoothed Index (SI) SI Lower CL. SI Upper CL. Trend Difference (TD) TD Lower CL. TD Upper CL. TREND CLASSIFICATION UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-All species UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants UK-Migrants 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 95.2 65 60.8 60.6 56.7 70.3 74.9 71.4 90.9 58.7 66.3 76.3 76 82.9 58.6 57.4 60.2 56.8 55.9 71.2 71.4 68.7 65.4 45.9 100 35.8 15.6 24.4 158 40.9 234 302 38 33.2 40.1 30.4 17.8 119 156 47.3 394 21 261 39.9 1870 42.2 198 73.9 645 76.5 299 835 229 172 732 263 68.44 68.37 68.29 68.21 68.12 68.02 67.90 67.76 67.60 67.40 67.19 66.94 66.66 66.36 66.04 65.69 65.34 64.97 64.60 64.22 63.83 63.43 63.03 62.62 13.08 27.45 41.82 56.19 70.56 84.93 99.30 113.67 128.04 142.41 156.78 171.15 185.52 199.89 214.26 228.63 243.00 257.37 271.74 286.11 300.48 314.85 329.22 343.59 357.96 372.33 386.70 401.07 415.44 429.81 444.18 458.55 63.89 63.95 63.98 63.97 63.93 63.87 63.77 63.64 63.48 63.27 63.03 62.75 62.43 62.05 61.62 61.13 60.59 59.99 59.33 58.60 57.80 56.93 55.99 54.98 -255.32 -228.28 -201.50 -175.01 -148.85 -123.09 -97.80 -73.06 -48.96 -25.62 -3.16 18.28 38.54 57.49 74.98 90.94 105.29 118.04 129.25 139.02 147.47 154.75 161.01 166.39 171.02 175.00 178.44 181.41 183.99 186.23 188.18 189.88 73.00 72.78 72.60 72.44 72.30 72.16 72.03 71.88 71.72 71.53 71.34 71.12 70.90 70.68 70.45 70.25 70.08 69.95 69.87 69.84 69.86 69.94 70.07 70.26 281.49 283.19 285.14 287.39 289.97 292.96 296.41 300.40 305.04 310.44 316.72 324.03 332.51 342.30 353.54 366.33 380.72 396.70 414.23 433.21 453.50 474.96 497.43 520.79 544.91 569.66 594.97 620.73 646.89 673.40 700.19 727.23 -5.82 -5.75 -5.67 -5.58 -5.49 -5.39 -5.27 -5.14 -4.97 -4.78 -4.56 -4.32 -4.04 -3.74 -3.41 -3.07 -2.71 -2.35 -1.97 -1.59 -1.20 -0.81 -0.41 0 445.47 431.10 416.73 402.36 387.99 373.62 359.25 344.88 330.51 316.14 301.77 287.40 273.03 258.66 244.29 229.92 215.55 201.18 186.81 172.44 158.07 143.70 129.33 114.96 100.59 86.22 71.85 57.48 43.11 28.74 14.37 0.00 -15.27 -15.03 -14.80 -14.56 -14.31 -14.04 -13.74 -13.40 -13.01 -12.57 -12.08 -11.52 -10.90 -10.22 -9.47 -8.66 -7.78 -6.85 -5.86 -4.81 -3.70 -2.53 -1.30 0 -15.86 -15.34 -14.83 -14.32 -13.81 -13.30 -12.79 -12.28 -11.76 -11.25 -10.74 -10.23 -9.72 -9.21 -8.70 -8.18 -7.67 -7.16 -6.65 -6.14 -5.63 -5.11 -4.60 -4.09 -3.58 -3.07 -2.56 -2.05 -1.53 -1.02 -0.51 0.00 3.63 3.54 3.46 3.39 3.32 3.25 3.19 3.13 3.07 3.01 2.95 2.89 2.82 2.74 2.64 2.52 2.36 2.16 1.92 1.63 1.29 0.91 0.48 0 906.80 877.55 848.30 819.05 789.79 760.54 731.29 702.04 672.79 643.54 614.28 585.03 555.78 526.53 497.28 468.03 438.77 409.52 380.27 351.02 321.77 292.52 263.27 234.01 204.76 175.51 146.26 117.01 87.75 58.50 29.25 0.00 stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable stable uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain uncertain