| Year | Value | | 2014 | -61.584254769778 | | 2013 | -60.881300739435 | | 2012 | -58.330635620874 | | 2011 | -63.217976846303 | | 2010 | -59.525702964544 | | 2009 | -60.715463586188 | | 2008 | -55.765304981993 | | 2007 | -63.185493978094 | | 2006 | -66.998927769423 | | 2005 | -75.66550285424 | | 2004 | -91.975213808224 | | 2003 | -94.200885293053 | | 2002 | -101.82898653729 | | 2001 | -104.71851744738 | | 2000 | -110.02159673248 | | 1999 | -117.64515782678 | | 1998 | -117.05282476819 | | 1997 | -122.45519302263 | | 1996 | -139.4878306424 | | 1995 | -135.52587937343 | | 1994 | -135.92732802753 | | 1993 | -153.83666637153 | | 1992 | -161.53026049757 | | 1991 | -173.5584434739 | | 1990 | -173.38894825783 | | 1989 | -186.54025340794 | | 1988 | -186.06537697917 | | 1987 | -219.22949556803 | | 1986 | -203.60660049684 | | 1985 | -166.51331426461 | | 1984 | -209.57869786822 | | 1983 | -194.07034224818 | | 1982 | -203.16278782803 | | 1981 | -317.20486480895 | | 1980 | -327.3510802769 | | 1979 | -300.30147696907 | | 1978 | -361.37995748447 | | 1977 | -382.90090178633 | | 1976 | -279.93337919841 | | 1975 | -367.0683361813 | | 1974 | -404.99673493775 | | 1973 | -432.42018377659 | | 1972 | -636.50515604801 | | 1971 | -657.24833443827 |
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