| Year | Value | | 2022 | 73.063780058431 | | 2021 | 72.636231546796 | | 2020 | 73.010580357314 | | 2019 | 72.300505094147 | | 2018 | 71.742312698157 | | 2017 | 70.226234224852 | | 2016 | 68.576867637077 | | 2015 | 69.840751807595 | | 2014 | 68.289141157937 | | 2013 | 67.558228696849 | | 2012 | 69.607059994701 | | 2011 | 69.889596888962 | | 2010 | 67.557057606946 | | 2009 | 67.859755516116 | | 2008 | 66.172544562376 | | 2007 | 65.288850640843 | | 2006 | 64.304501054561 | | 2005 | 63.416820378251 | | 2004 | 62.774407167651 | | 2003 | 61.759235432268 | | 2002 | 61.556891647189 | | 2001 | 61.341146530647 | | 2000 | 61.155417457494 | | 1999 | 60.616097113358 | | 1998 | 60.320580779272 | | 1997 | 59.859764929838 | | 1996 | 59.832952243076 | | 1995 | 60.105029250711 | | 1994 | 60.286090313451 | | 1993 | 60.892326870601 | | 1992 | 61.53178471193 | | 1991 | 61.83024809269 |
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