| Year | Value | | 2017 | 89.120849297738 | | 2016 | 90.262798649327 | | 2015 | 89.185930952883 | | 2014 | 86.182238808314 | | 2013 | 88.082060817626 | | 2012 | 87.319232321161 | | 2011 | 84.997830802603 | | 2010 | 85.325650452656 | | 2009 | 91.23543906058 | | 2008 | 89.506103587581 | | 2007 | 79.832037225195 | | 2006 | 86.361159518307 | | 2005 | 89.129193852125 | | 2004 | 87.99128561942 | | 2003 | 91.234685514021 | | 2002 | 95.522941438654 | | 2001 | 97.847376960419 | | 2000 | 91.865164495059 | | 1999 | 97.162326189936 | | 1998 | 99.046130603489 | | 1990 | 86.700001197051 |
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