| Year | Value | | 2021 | 5,775.8395830056 | | 2020 | 5,367.9490343507 | | 2019 | 6,818.4920461384 | | 2018 | 6,984.288498421 | | 2017 | 7,642.2287430439 | | 2016 | 6,565.2069807303 | | 2015 | 6,666.7470791263 | | 2014 | 9,242.5778717324 | | 2013 | 9,456.544248826 | | 2012 | 9,351.3111303543 | | 2011 | 10,260.08084351 | | 2010 | 8,878.0246763329 | | 2009 | 6,936.075263333 | | 2008 | 7,170.0159883893 | | 2007 | 6,067.2978189434 | | 2006 | 4,830.4105530738 | | 2005 | 3,898.8675732753 | | 2004 | 2,976.6482945621 | | 2003 | 2,494.6590582377 | | 2002 | 2,305.2397560704 | | 2001 | 2,580.6999503041 | | 2000 | 3,082.3583752399 | | 1999 | 2,867.9653654609 | | 1998 | 4,311.4692123248 | | 1997 | 4,559.436206042 | | 1996 | 4,524.0690936766 | | 1995 | 4,110.3864461171 | | 1994 | 2,739.9730746718 | | 1993 | 1,962.2402459429 | | 1992 | 1,779.0485948243 | | 1991 | 1,888.2132478773 | | 1990 | 2,159.5541264709 | | 1989 | 2,172.414331482 | | 1988 | 1,615.3354534364 | | 1987 | 1,469.0007430219 | | 1986 | 1,369.2633658513 | | 1985 | 1,116.1778813194 | | 1984 | 1,284.4549433015 | | 1983 | 1,270.7004550769 | | 1982 | 1,836.6246794743 | | 1981 | 1,778.5279809442 | | 1980 | 1,638.0863870709 | | 1979 | 1,635.8824271617 | | 1978 | 1,497.9388081445 | | 1977 | 1,356.6829479775 | | 1976 | 1,211.7756482971 | | 1975 | 1,007.0811241418 |
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