| Year | Value | | 2024 | 115.70858585207 | | 2023 | 107.86177288158 | | 2022 | 94.586893236855 | | 2021 | 86.425796653815 | | 2020 | 89.471085773903 | | 2019 | 86.898274735177 | | 2018 | 86.003966969083 | | 2017 | 86.822855871869 | | 2016 | 87.744025820421 | | 2015 | 87.930292496052 | | 2014 | 87.494932187398 | | 2013 | 86.72940322497 | | 2012 | 86.268987298506 | | 2011 | 88.282359762284 | | 2010 | 85.078037557518 | | 2009 | 87.057023195876 | | 2008 | 88.937330506872 | | 2007 | 87.111779250186 | | 2006 | 88.03293586992 | | 2005 | 86.550496098544 | | 2004 | 90.46723974557 | | 2003 | 92.17940486669 | | 2002 | 92.478754112026 | | 2001 | 91.426154584249 | | 2000 | 90.312329627618 | | 1999 | 90.936908250389 | | 1998 | 90.796342409519 | | 1997 | 87.952695846911 | | 1996 | 86.100182070707 | | 1995 | 94.903183990015 | | 1994 | 95.224577355801 | | 1993 | 97.323528314672 | | 1992 | 95.852287183573 | | 1991 | 92.70560856681 | | 1990 | 84.902874995178 | | 1989 | 88.135143480973 | | 1988 | 87.403458366058 | | 1987 | 88.93817515433 | | 1986 | 87.675964638946 | | 1985 | 82.699037804608 | | 1984 | 86.970356011077 | | 1983 | 86.73739814555 | | 1982 | 86.604186387145 | | 1981 | 86.137388479462 | | 1980 | 85.829673405222 | | 1979 | 86.455800017285 | | 1978 | 86.352889671935 | | 1977 | 86.275987869744 | | 1976 | 86.210348011987 | | 1975 | 86.224939984679 |
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