| Year | Value | | 2014 | -177.12435791379 | | 2013 | -189.3454690039 | | 2012 | -212.76593180302 | | 2011 | -248.73482364809 | | 2010 | -275.46348609999 | | 2009 | -275.42561004865 | | 2008 | -334.70246250619 | | 2007 | -345.94471998821 | | 2006 | -375.07931992685 | | 2005 | -414.04534662303 | | 2004 | -407.11578574623 | | 2003 | -405.04180181467 | | 2002 | -394.66251191076 | | 2001 | -405.60698411703 | | 2000 | -426.80354276348 | | 1999 | -415.38475924483 | | 1998 | -410.45156356039 | | 1997 | -405.61790064407 | | 1996 | -379.86250141589 | | 1995 | -340.14454201763 | | 1994 | -332.95060010238 | | 1993 | -335.21701792765 | | 1992 | -333.76028010792 | | 1991 | -337.10580262256 | | 1990 | -351.21256367392 | | 1989 | -357.44405424686 | | 1988 | -335.35535720832 | | 1987 | -348.65274421776 | | 1986 | -319.62583870903 | | 1985 | -355.11755474675 | | 1984 | -353.23103383822 | | 1983 | -332.10593939306 | | 1982 | -324.3414981847 | | 1981 | -451.49890660862 | | 1980 | -486.65326999289 | | 1979 | -588.90170177676 | | 1978 | -700.47750592722 | | 1977 | -780.26693419168 | | 1976 | -833.00554439348 | | 1975 | -860.74181294659 | | 1974 | -927.05731076192 | | 1973 | -1,071.4097217485 | | 1972 | -1,261.3542935142 | | 1971 | -1,098.0529727424 |
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