| Year | Value | | 2021 | 4,704.2840342503 | | 2020 | 4,397.2723644382 | | 2019 | 5,040.6717742128 | | 2018 | 4,947.3995286948 | | 2017 | 4,714.8166336434 | | 2016 | 4,412.1826686013 | | 2015 | 4,515.1467177576 | | 2014 | 4,465.353642969 | | 2013 | 4,590.194491692 | | 2012 | 4,843.2333388805 | | 2011 | 4,622.816739744 | | 2010 | 4,248.8251552715 | | 2009 | 3,820.0181016597 | | 2008 | 4,386.1425203314 | | 2007 | 4,066.4742503376 | | 2006 | 3,813.6878968732 | | 2005 | 3,603.18644263 | | 2004 | 3,296.1720365863 | | 2003 | 3,057.712457633 | | 2002 | 3,168.1596947889 | | 2001 | 3,056.2378131801 | | 2000 | 3,031.336983775 | | 1999 | 3,004.3763498452 | | 1998 | 3,025.4930996687 | | 1997 | 2,928.3117628279 | | 1996 | 2,584.9302441524 | | 1995 | 2,267.7805995215 | | 1994 | 1,876.6350822694 | | 1993 | 1,955.5869498784 | | 1992 | 1,200.3610305667 | | 1991 | 1,354.1162979404 | | 1990 | 1,556.3029319958 | | 1989 | 1,516.2530892168 | | 1988 | 1,308.8415678334 | | 1987 | 1,092.1502320968 | | 1986 | 901.99872503628 | | 1985 | 645.64478742136 | | 1984 | 769.5458379438 | | 1983 | 1,311.928778911 | | 1982 | 1,175.1729359604 | | 1981 | 1,065.6291398167 | | 1980 | 934.57383081232 | | 1979 | 883.46002158837 | | 1978 | 1,003.9162467488 | | 1977 | 1,294.5517454102 | | 1976 | 1,210.702529411 | | 1975 | 1,243.6174572655 | | 1974 | 1,064.0901835878 | | 1973 | 843.60513219542 | | 1972 | 844.54494922359 | | 1971 | 664.72083736529 |
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