| Year | Value | | 2020 | 7,197.8019546246 | | 2019 | 7,621.5231265711 | | 2018 | 8,063.6011977865 | | 2017 | 8,921.2112197411 | | 2016 | 9,193.5742056656 | | 2015 | 9,294.2728117552 | | 2014 | 10,269.293408231 | | 2013 | 10,665.18720189 | | 2012 | 9,895.7287683168 | | 2011 | 9,534.7373444097 | | 2010 | 8,905.3166120118 | | 2009 | 7,429.9722239224 | | 2008 | 9,024.5958073786 | | 2007 | 8,093.6604017551 | | 2006 | 6,615.6962961972 | | 2005 | 6,059.7566365296 | | 2004 | 4,897.8976882302 | | 2003 | 3,764.3967633923 | | 2002 | 2,865.1920204052 | | 2001 | 2,427.7784928813 | | 2000 | 3,462.8577086996 | | 1999 | 3,270.8551011499 | | 1998 | 3,613.11762118 | | 1997 | 2,507.675947527 | | 1996 | 2,422.5787731472 | | 1995 | 2,284.8280689857 | | 1994 | 1,765.3837072785 | | 1993 | 2,546.2642860312 | | 1992 | 2,262.7531533087 | | 1991 | 2,173.3877366143 | | 1990 | 2,230.6811006012 | | 1989 | 1,593.3802596524 | | 1988 | 1,352.5890789212 | | 1987 | 1,338.2666534054 | | 1986 | 1,208.2189816187 | | 1985 | 1,095.6152601358 | | 1984 | 997.0576281076 | | 1983 | 1,050.3222730516 | | 1982 | 1,127.1444540539 | | 1981 | 1,270.5138917268 | | 1980 | 1,260.0978844109 | | 1979 | 1,682.2885245326 | | 1978 | 1,258.1151188928 | | 1977 | 1,159.0526618853 | | 1976 | 1,030.6328452795 | | 1975 | 919.57377846255 | | 1974 | 745.05242893496 |
|