| Year | Value | | 2013 | 87.914438502674 | | 2012 | 83.518012379105 | | 2011 | 84.337152472292 | | 2010 | 88.823425958495 | | 2009 | 70.859913243174 | | 2008 | 82.573030886415 | | 2007 | 85.570756733647 | | 2006 | 84.520581710624 | | 2005 | 85.091743119266 | | 2004 | 27.386091127098 | | 2003 | 36.165577342048 | | 2002 | 36.405886909373 | | 2001 | 41.371841155235 | | 2000 | 43.789308176101 | | 1999 | 47.195512820513 | | 1998 | 48.139711465452 | | 1997 | 45.603944124897 | | 1996 | 41.054451166811 | | 1995 | 45.118483412322 | | 1994 | 46.999076638966 | | 1993 | 47.801147227533 | | 1992 | 50.571131879543 | | 1991 | 46.285714285714 | | 1990 | 44.121212121212 |
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