| Year | Value | | 2014 | -191.5238831163 | | 2013 | -219.73950818885 | | 2012 | -211.9563536301 | | 2011 | -232.7374709148 | | 2010 | -186.50972057731 | | 2009 | -211.6089571872 | | 2008 | -266.00825615506 | | 2007 | -289.45173379537 | | 2006 | -316.27965525767 | | 2005 | -365.87321401283 | | 2004 | -352.90273552121 | | 2003 | -349.86842246924 | | 2002 | -290.77402706836 | | 2001 | -361.93019758734 | | 2000 | -386.2477845196 | | 1999 | -372.66790144135 | | 1998 | -420.66943861245 | | 1997 | -438.43668518414 | | 1996 | -418.53616553701 | | 1995 | -449.35271981432 | | 1994 | -449.63235085856 | | 1993 | -490.73584263467 | | 1992 | -520.3274797279 | | 1991 | -586.6820050796 | | 1990 | -535.18825062376 | | 1989 | -376.34910204156 | | 1988 | -373.19807175786 | | 1987 | -352.52173083095 | | 1986 | -522.09564640433 | | 1985 | -336.4309715906 | | 1984 | -478.3267126852 | | 1983 | -447.65666585523 | | 1982 | -662.13794194416 | | 1981 | -1,155.3039939356 | | 1980 | -1,615.8578563424 | | 1979 | -2,115.5831501272 | | 1978 | -2,458.4249693883 | | 1977 | -4,085.8696426523 | | 1976 | -4,266.2315354703 | | 1975 | -4,057.425224543 | | 1974 | -5,272.4064262308 | | 1973 | -5,271.9000484317 | | 1972 | -4,828.8243088906 | | 1971 | -3,218.0269966725 |
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