| Year | Value | | 2021 | 82.91407928 | | 2020 | 90.21945812 | | 2019 | 92.73039781 | | 2018 | 88.74635089 | | 2017 | 91.72654724 | | 2016 | 93.18272128 | | 2015 | 91.05802839 | | 2014 | 89.10683302 | | 2013 | 88.21942891 | | 2012 | 79.4964 | | 2011 | 79.05411352 | | 2010 | 78.21 | | 2009 | 78 | | 2008 | 75.4 | | 2007 | 74.3 | | 2006 | 68.68527032 | | 2005 | 66.9210661 | | 2004 | 62.39392963 | | 2003 | 48.43526589 | | 2002 | 46.59420112 | | 2001 | 38.53206086 | | 2000 | 29.99074036 | | 1999 | 21.39129031 | | 1998 | 13.41404088 | | 1997 | 9.16307714 | | 1996 | 4.372981968 | | 1995 | 1.594363148 | | 1994 | 0.799684291 | | 1993 | 0.401277526 | | 1992 | 0.096678025 | | 1991 | 0.040438041 | | 1990 | 0.020293683 |
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