| Year | Value | | 2014 | 5,916.4304203131 | | 2013 | 5,646.2312177964 | | 2012 | 5,317.1641791045 | | 2011 | 5,236.4278729378 | | 2010 | 5,501.8872752863 | | 2009 | 5,483.630228106 | | 2008 | 5,296.4010790184 | | 2007 | 5,000.6667555674 | | 2006 | 4,934.599655254 | | 2005 | 4,836.2202023667 | | 2004 | 4,596.7404931049 | | 2003 | 4,593.4772622875 | | 2002 | 4,481.5717768536 | | 2001 | 4,400.9956350781 | | 2000 | 4,361.7749900869 | | 1999 | 4,188.4816753927 | | 1998 | 4,052.6849037487 | | 1997 | 3,918.1541140618 | | 1996 | 3,892.1828962206 | | 1995 | 3,830.4392236977 | | 1994 | 3,775.3830364343 | | 1993 | 3,687.587580205 | | 1992 | 3,562.8131378735 | | 1991 | 3,223.654957759 | | 1990 | 2,708.9358275067 | | 1989 | 2,780.9881537128 | | 1988 | 2,357.1428571429 | | 1987 | 2,192.9824561404 | | 1986 | 2,210.0610397811 | | 1985 | 2,127.3627676641 | | 1984 | 2,049.465054884 | | 1983 | 2,044.706290071 | | 1982 | 1,974.8466895333 | | 1981 | 1,873.763836358 | | 1980 | 1,809.7027911185 | | 1979 | 1,817.0382276889 | | 1978 | 1,720.2036159382 | | 1977 | 1,729.1879874369 | | 1976 | 1,775.4420850792 | | 1975 | 1,751.6891288028 | | 1974 | 1,655.9271392059 | | 1973 | 1,705.4938674795 | | 1972 | 1,646.9640961827 | | 1971 | 1,662.4182644353 |
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