| Year | Value | | 2014 | 6,602.6574793835 | | 2013 | 6,539.2073745255 | | 2012 | 6,617.1341613974 | | 2011 | 6,485.759030014 | | 2010 | 6,409.8943651649 | | 2009 | 6,095.3802760254 | | 2008 | 6,399.683749112 | | 2007 | 6,286.0493917606 | | 2006 | 6,098.5334761807 | | 2005 | 5,770.1006364225 | | 2004 | 5,633.8455003909 | | 2003 | 5,478.1304581838 | | 2002 | 5,304.4152595599 | | 2001 | 5,274.3633046315 | | 2000 | 5,198.4057040127 | | 1999 | 4,998.8256613589 | | 1998 | 4,848.0273525195 | | 1997 | 4,935.6199049536 | | 1996 | 5,016.444066406 | | 1995 | 5,101.5533956359 | | 1994 | 5,188.2139545229 | | 1993 | 5,726.4515926869 | | 1992 | 6,113.6799714891 | | 1991 | 6,551.2998161599 | | 1990 | 6,687.7270110301 |
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