| Year | Value | | 2021 | 8,993.5474104878 | | 2020 | 7,211.5410256758 | | 2019 | 8,244.0686784262 | | 2018 | 9,879.584609645 | | 2017 | 12,578.14613707 | | 2016 | 10,865.789888449 | | 2015 | 11,761.781230478 | | 2014 | 10,265.670657533 | | 2013 | 10,909.098203047 | | 2012 | 10,884.703997005 | | 2011 | 10,725.162544547 | | 2010 | 8,670.4143460477 | | 2009 | 6,837.5298582 | | 2008 | 7,573.7082006048 | | 2007 | 6,111.1146557582 | | 2006 | 4,894.9317474461 | | 2005 | 3,812.0382192277 | | 2004 | 3,206.8628791191 | | 2003 | 2,702.543510334 | | 2002 | 1,995.2588660437 | | 2001 | 6,002.2890472308 | | 2000 | 6,430.9333156754 | | 1999 | 6,548.7400384951 | | 1998 | 7,112.761604335 | | 1997 | 7,074.4042529882 | | 1996 | 6,696.4738908319 | | 1995 | 6,396.3742639798 | | 1994 | 6,584.9513456619 | | 1993 | 6,198.7498627263 | | 1992 | 6,077.9055605692 | | 1991 | 5,041.3710581589 | | 1990 | 3,696.2128734358 | | 1989 | 1,927.8939457602 | | 1988 | 3,489.448243843 | | 1987 | 3,107.4349592588 | | 1986 | 3,174.7705251949 | | 1985 | 2,488.7196976888 | | 1984 | 2,263.299264787 | | 1983 | 3,021.0237642028 | | 1982 | 2,471.0227018717 | | 1981 | 2,390.902506583 | | 1980 | 2,403.2799253471 | | 1979 | 2,222.6373551772 | | 1978 | 1,944.7410567186 | | 1977 | 1,943.5263755344 | | 1976 | 1,785.2441540378 | | 1975 | 1,893.8464982605 | | 1974 | 2,649.7235780697 | | 1973 | 1,973.9696524015 | | 1972 | 1,301.0625437284 | | 1971 | 1,307.003431574 | | 1970 | 1,200.2886627161 |
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