| Year | Value | | 2014 | 11,562.988522684 | | 2013 | 11,271.10654471 | | 2012 | 10,988.960260562 | | 2011 | 10,732.80463849 | | 2010 | 10,695.289934142 | | 2009 | 10,518.797033873 | | 2008 | 11,457.090997806 | | 2007 | 12,029.545906566 | | 2006 | 12,651.067962671 | | 2005 | 13,161.198815322 | | 2004 | 12,184.289888737 | | 2003 | 12,036.891596387 | | 2002 | 11,969.765979434 | | 2001 | 11,601.53529126 | | 2000 | 11,782.924056882 | | 1999 | 11,700.165581782 | | 1998 | 10,817.389161044 | | 1997 | 9,655.4446475189 | | 1996 | 9,388.4523668392 | | 1995 | 9,329.9556119422 | | 1994 | 9,274.271110989 | | 1993 | 8,894.050422708 | | 1992 | 8,036.4572676612 | | 1991 | 7,862.0462332135 | | 1990 | 8,179.876230889 | | 1989 | 7,928.7213144031 | | 1988 | 8,196.9209131659 | | 1987 | 8,059.4755154009 | | 1986 | 8,113.9949220295 | | 1985 | 8,090.4014103293 | | 1984 | 7,819.1222251861 | | 1983 | 7,620.5667225826 | | 1982 | 7,098.4778945349 | | 1981 | 6,099.0019814939 | | 1980 | 5,783.7498816624 | | 1979 | 5,109.7911612281 | | 1978 | 4,347.8206874797 | | 1977 | 3,887.6101524911 | | 1976 | 2,938.8922085979 | | 1975 | 2,342.6832096048 | | 1974 | 1,782.683375512 |
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