| Year | Value | | 2014 | 3,895.4361560974 | | 2013 | 3,893.5061115339 | | 2012 | 3,820.3710566816 | | 2011 | 3,596.1066459496 | | 2010 | 3,318.3052478564 | | 2009 | 3,306.8687595595 | | 2008 | 3,347.6654089539 | | 2007 | 3,346.4807270912 | | 2006 | 3,226.3465685517 | | 2005 | 3,097.0656452911 | | 2004 | 3,063.8721545544 | | 2003 | 2,896.0637897002 | | 2002 | 2,726.2375754996 | | 2001 | 2,627.3549215285 | | 2000 | 2,497.752869224 | | 1999 | 2,390.8157462799 | | 1998 | 2,174.2055707833 | | 1997 | 2,066.1356531026 | | 1996 | 1,922.8238984644 | | 1995 | 1,741.0248435228 | | 1994 | 1,583.7390964004 | | 1993 | 1,508.9596757798 | | 1992 | 1,450.4839070004 | | 1991 | 1,307.4820757642 | | 1990 | 1,231.2945013021 | | 1989 | 1,202.33514279 | | 1988 | 1,115.3867560421 | | 1987 | 1,048.629474079 | | 1986 | 1,022.4937436584 | | 1985 | 982.60675707644 | | 1984 | 961.3296544103 | | 1983 | 901.26399896197 | | 1982 | 882.5815115392 | | 1981 | 914.70647803807 | | 1980 | 898.7929025614 | | 1979 | 872.58591419519 | | 1978 | 830.41921939695 | | 1977 | 790.43845678628 | | 1976 | 765.30312398975 | | 1975 | 727.9456209113 | | 1974 | 797.2123444641 | | 1973 | 754.76515841046 | | 1972 | 784.56380568641 | | 1971 | 758.08427926106 |
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