| Year | Value | | 2021 | 5,061.4691768183 | | 2020 | 4,563.263687988 | | 2019 | 4,923.831542912 | | 2018 | 4,821.0706755537 | | 2017 | 4,768.2639671748 | | 2016 | 4,524.2180516659 | | 2015 | 4,548.2114658135 | | 2014 | 5,360.0850579723 | | 2013 | 5,124.2791733042 | | 2012 | 5,226.0349980778 | | 2011 | 5,653.8686641689 | | 2010 | 4,531.8127432564 | | 2009 | 3,789.6768893569 | | 2008 | 3,937.963469624 | | 2007 | 3,989.3776584639 | | 2006 | 3,742.4160818874 | | 2005 | 3,822.440855461 | | 2004 | 3,261.0220105025 | | 2003 | 2,866.892886098 | | 2002 | 2,273.5082040572 | | 2001 | 2,693.9153473556 | | 2000 | 2,727.690404966 | | 1999 | 2,693.4223569069 | | 1998 | 2,596.094509825 | | 1997 | 2,592.8113170616 | | 1996 | 2,457.611008065 | | 1995 | 2,562.0243866421 | | 1994 | 2,269.0289826555 | | 1993 | 2,632.0528818377 | | 1992 | 2,569.602891807 | | 1991 | 2,483.7127816384 | | 1990 | 2,381.5122431751 | | 1989 | 1,830.0337276003 | | 1988 | 1,624.3306909017 | | 1987 | 1,225.0477116357 | | 1986 | 943.90688730946 | | 1985 | 776.67201864016 | | 1984 | 886.74153602754 | | 1983 | 917.10595094128 | | 1982 | 870.44648613524 | | 1981 | 975.16890289338 | | 1980 | 909.17233069731 | | 1979 | 774.79526473933 | | 1978 | 585.70216656345 | | 1977 | 451.91704605083 | | 1976 | 384.59808881719 | | 1975 | 394.6989665289 | | 1974 | 362.26701790844 | | 1973 | 312.77928984482 | | 1972 | 224.46294118262 | | 1971 | 187.6338163231 |
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