| Year | Value | | 2021 | 2,915.3792227624 | | 2020 | 2,412.8841373863 | | 2019 | 2,534.3104981369 | | 2018 | 3,242.0173320499 | | 2017 | 3,085.0686296803 | | 2016 | 3,461.5485367137 | | 2015 | 4,149.2701975325 | | 2014 | 5,265.873694158 | | 2013 | 5,156.2200808533 | | 2012 | 4,229.1658482606 | | 2011 | 4,223.8999842916 | | 2010 | 2,281.4737134977 | | 2009 | 4,574.8692753354 | | 2008 | 6,091.7237163074 | | 2007 | 4,632.4607936511 | | 2006 | 3,394.0936925072 | | 2005 | 115.44515386141 | | 2000 | -115.77516230855 | | 1999 | 214.48021012678 | | 1998 | 135.65927331999 | | 1997 | 233.82819429862 | | 1996 | 146.85676288992 | | 1995 | 114.27899714619 | | 1994 | 106.09603061 | | 1993 | 232.83400616 | | 1992 | 248.8736996933 | | 1991 | 206.15798056036 | | 1990 | 199.8589954596 | | 1989 | 135.09393042655 | | 1988 | 172.53311159858 | | 1987 | 161.73461144601 | | 1986 | 135.8456006434 | | 1985 | 121.14146582554 | | 1984 | 100.84190345356 | | 1983 | 82.989065164927 | | 1982 | 59.244247454304 | | 1981 | 65.238754919845 | | 1980 | 136.17550223578 |
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