| Year | Value | | 2021 | 4,308.9130999324 | | 2020 | 3,977.5122596978 | | 2019 | 4,006.9071074863 | | 2018 | 3,845.2992260701 | | 2017 | 3,791.60178841 | | 2016 | 3,560.9038871897 | | 2015 | 3,439.8471197907 | | 2014 | 3,212.6990278048 | | 2013 | 3,004.2438235228 | | 2012 | 2,871.7343020368 | | 2011 | 2,722.6630617756 | | 2010 | 2,417.9463604859 | | 2009 | 2,268.3893658263 | | 2008 | 2,410.7073551296 | | 2007 | 2,130.6725723902 | | 2006 | 1,942.6315570868 | | 2005 | 1,802.8445776211 | | 2004 | 1,631.4013823551 | | 2003 | 1,536.7994222086 | | 2002 | 1,495.7695426156 | | 2001 | 1,401.5026884855 | | 2000 | 1,496.3297024043 | | 1999 | 1,464.6984444556 | | 1998 | 1,599.7279196299 | | 1997 | 1,497.9833306916 | | 1996 | 1,355.5880453131 | | 1995 | 1,307.2442491591 | | 1994 | 1,189.08484739 | | 1993 | 1,072.8247877534 | | 1992 | 1,004.8727172997 | | 1991 | 933.43803777939 | | 1990 | 765.52750815081 | | 1989 | 870.77291046833 | | 1988 | 830.95574196686 | | 1987 | 770.02883073592 | | 1986 | 803.42389624402 | | 1985 | 1,121.8792396101 | | 1984 | 1,117.4426407075 | | 1983 | 1,104.9054197194 | | 1982 | 1,094.8339040918 | | 1981 | 1,116.295411257 | | 1980 | 1,049.0260815482 | | 1979 | 950.884825324 | | 1978 | 856.51468944298 | | 1977 | 791.7704525653 | | 1976 | 641.06120783009 | | 1975 | 543.04182201379 | | 1974 | 483.9820415009 | | 1973 | 401.99658753681 | | 1972 | 335.10736938088 | | 1971 | 324.24575154834 |
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