| Year | Value | | 2021 | 12,502.122867685 | | 2020 | 11,983.324314549 | | 2019 | 12,834.528683552 | | 2018 | 13,303.373735208 | | 2017 | 11,682.784693016 | | 2016 | 11,524.253845717 | | 2015 | 12,240.889548319 | | 2014 | 12,603.712110808 | | 2013 | 12,617.4015934 | | 2012 | 12,859.287101328 | | 2011 | 11,923.262408339 | | 2010 | 12,379.789313281 | | 2009 | 9,843.8366528703 | | 2008 | 13,377.590232224 | | 2007 | 9,378.8164247628 | | 2006 | 8,326.426920818 | | 2005 | 6,764.5947876579 | | 2004 | 5,966.8908488943 | | 2003 | 5,522.1105211022 | | 2002 | 5,193.1271105104 | | 2001 | 4,712.6474033706 | | 2000 | 4,380.9296023561 | | 1999 | 4,092.7316794235 | | 1998 | 4,072.0239558971 | | 1997 | 4,368.9923744525 | | 1996 | 4,098.2962849247 | | 1995 | 4,003.4450534087 | | 1994 | 3,868.557995921 | | 1993 | 3,757.9000633726 | | 1992 | 3,912.4528455062 | | 1991 | 3,782.041496885 | | 1990 | 3,316.746322027 | | 1989 | 2,981.707455499 | | 1988 | 3,068.0557914242 | | 1987 | 3,040.2258605271 | | 1986 | 3,415.5416952047 | | 1985 | 4,630.858036077 | | 1984 | 4,528.53156827 | | 1983 | 4,189.6865480032 | | 1982 | 4,499.673174027 | | 1981 | 4,037.6829704683 | | 1980 | 3,102.0190799654 | | 1979 | 1,403.8828788317 | | 1978 | 1,667.0577029092 | | 1977 | 1,599.8306404847 | | 1976 | 1,373.9101194555 | | 1975 | 999.03595131807 | | 1974 | 683.00646980342 | | 1973 | 117.66066383533 | | 1972 | 213.27879247022 | | 1971 | 196.02440377059 | | 1970 | 166.15214696759 |
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