| Year | Value | | 2014 | 3,360.899316395 | | 2013 | 3,402.2941989336 | | 2012 | 3,413.3705496501 | | 2011 | 3,270.5144501598 | | 2010 | 3,068.1527164946 | | 2009 | 2,785.8938817613 | | 2008 | 2,843.2374970584 | | 2007 | 2,236.8456509133 | | 2006 | 2,212.6194467047 | | 2005 | 2,197.691081033 | | 2004 | 2,109.6537174802 | | 2003 | 2,008.4818501648 | | 2002 | 1,873.3282361656 | | 2001 | 1,851.7582644963 | | 2000 | 1,822.2929402898 | | 1999 | 1,653.4979174161 | | 1998 | 1,610.4264847721 | | 1997 | 1,277.9945787139 | | 1996 | 1,085.0230733739 | | 1995 | 979.32903829249 | | 1994 | 935.32465254244 | | 1993 | 732.18714470093 | | 1992 | 1,100.3968912911 | | 1991 | 2,043.8052179444 | | 1990 | 2,917.4667524047 |
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