| Year | Value | | 2014 | 3,690.1036829597 | | 2013 | 3,657.1246793066 | | 2012 | 3,704.3090406142 | | 2011 | 3,632.8785603092 | | 2010 | 3,566.1730126923 | | 2009 | 3,299.4609021774 | | 2008 | 3,481.7435165987 | | 2007 | 3,393.9085361051 | | 2006 | 3,365.981865135 | | 2005 | 3,245.3720878133 | | 2004 | 3,174.0530923174 | | 2003 | 3,063.0569385824 | | 2002 | 3,000.7456250783 | | 2001 | 3,009.4024816718 | | 2000 | 2,996.3094750196 | | 1999 | 3,005.3642570495 | | 1998 | 3,015.400275001 | | 1997 | 2,952.9229400383 | | 1996 | 2,806.6151231415 | | 1995 | 2,790.0207488235 | | 1994 | 3,068.3619904458 | | 1993 | 3,450.2224327452 | | 1992 | 3,912.7017453191 | | 1991 | 4,426.0132135903 | | 1990 | 4,380.7513493503 |
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