| Year | Value | | 2014 | 3,418.5693170559 | | 2013 | 3,600.2257040987 | | 2012 | 3,640.5534825677 | | 2011 | 3,662.444428079 | | 2010 | 3,549.8445512358 | | 2009 | 3,227.9532614047 | | 2008 | 3,534.3579922681 | | 2007 | 3,528.9244497156 | | 2006 | 3,399.5196951615 | | 2005 | 3,246.0342835822 | | 2004 | 3,151.1459691603 | | 2003 | 2,997.9744608516 | | 2002 | 2,844.8127243272 | | 2001 | 2,791.7653054514 | | 2000 | 2,778.400252153 | | 1999 | 2,792.1045214801 | | 1998 | 2,839.4539780036 | | 1997 | 2,958.5568420345 | | 1996 | 3,060.3355412885 | | 1995 | 3,348.8958084204 | | 1994 | 3,475.137419253 | | 1993 | 3,953.2802342696 | | 1992 | 4,313.5239614653 | | 1991 | 4,643.2630455476 | | 1990 | 4,787.5370485283 |
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