| Year | Value | | 2014 | -83.67054072068 | | 2013 | -83.84123984904 | | 2012 | -77.856109629523 | | 2011 | -80.004298997537 | | 2010 | -85.847244004456 | | 2009 | -84.021628710157 | | 2008 | -82.133124364702 | | 2007 | -84.232474302143 | | 2006 | -82.950425259188 | | 2005 | -84.628703899135 | | 2004 | -81.082634082109 | | 2003 | -73.472162406874 | | 2002 | -67.91521340038 | | 2001 | -61.056556740837 | | 2000 | -57.926226448823 | | 1999 | -57.982716992781 | | 1998 | -59.834798043459 | | 1997 | -55.06124884964 | | 1996 | -53.153869615802 | | 1995 | -51.978495308034 | | 1994 | -50.909078089569 | | 1993 | -40.772258879698 | | 1992 | -43.119949333165 | | 1991 | -39.805183176262 | | 1990 | -47.078855623858 |
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