| Year | Value | | 2021 | 7,443.5335179872 | | 2020 | 6,535.7271863229 | | 2019 | 7,866.6144422457 | | 2018 | 7,618.0787543439 | | 2017 | 7,373.2245459909 | | 2016 | 6,958.9273628128 | | 2015 | 7,687.1321477311 | | 2014 | 8,590.4561955355 | | 2013 | 8,273.1862923997 | | 2012 | 7,902.193001567 | | 2011 | 7,895.6120456463 | | 2010 | 7,366.4535116167 | | 2009 | 6,300.8143981311 | | 2008 | 7,868.4940727411 | | 2007 | 7,668.3016452362 | | 2006 | 7,195.6337665333 | | 2005 | 6,543.6647418242 | | 2004 | 6,036.2616987854 | | 2003 | 5,732.848954895 | | 2002 | 6,286.1525224378 | | 2001 | 6,276.2706081421 | | 2000 | 5,915.8217101188 | | 1999 | 5,126.5754884806 | | 1998 | 4,563.2068052882 | | 1997 | 4,373.860208357 | | 1996 | 3,531.5451096218 | | 1995 | 3,126.5420679558 | | 1994 | 4,979.2457831752 | | 1993 | 4,810.5660149714 | | 1992 | 3,476.8131847759 | | 1991 | 3,042.0813748936 | | 1990 | 2,481.3311258053 | | 1989 | 2,112.3009650151 | | 1988 | 1,728.9201601655 | | 1987 | 1,363.3007025162 | | 1986 | 1,267.8721496547 | | 1985 | 1,929.3699531273 | | 1984 | 1,810.482043761 | | 1983 | 1,554.4808579874 | | 1982 | 1,997.9437403455 | | 1981 | 3,102.6810186771 | | 1980 | 2,459.6091448878 | | 1979 | 1,671.0149871474 | | 1978 | 1,340.0014760335 | | 1977 | 1,104.1840132696 | | 1976 | 1,246.9903099859 |
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