| Year | Value | | 2022 | 86.044061287367 | | 2021 | 85.937194278582 | | 2020 | 85.478101959021 | | 2019 | 85.601390891946 | | 2018 | 84.984240309884 | | 2017 | 84.394095846845 | | 2016 | 83.769941130684 | | 2015 | 83.534552999699 | | 2014 | 83.195414482973 | | 2013 | 82.98085596352 | | 2012 | 83.171491393694 | | 2011 | 83.186477760879 | | 2010 | 82.791568978751 | | 2009 | 82.499928651861 | | 2008 | 83.23919904958 | | 2007 | 83.742002931785 | | 2006 | 83.770478367891 | | 2005 | 82.960494722214 | | 2004 | 82.080078657869 | | 2003 | 82.325161761753 | | 2002 | 81.976542502803 | | 2001 | 81.656624343475 | | 2000 | 80.889343403154 | | 1999 | 80.71568627451 | | 1998 | 79.684538358532 | | 1997 | 79.248205156933 | | 1996 | 79.129694967845 | | 1995 | 77.913584408058 | | 1994 | 77.397187576747 | | 1993 | 76.640286302182 | | 1992 | 76.04346330547 | | 1991 | 76.528946120811 |
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