| Year | Value | | 2022 | 63.921615969087 | | 2021 | 65.045606451622 | | 2020 | 65.445888308988 | | 2019 | 66.406906495484 | | 2018 | 66.82277924901 | | 2017 | 68.132860546797 | | 2016 | 69.135381044902 | | 2015 | 69.987542079176 | | 2014 | 67.334569544427 | | 2013 | 67.800113848728 | | 2012 | 66.14883461941 | | 2011 | 66.465415757118 | | 2010 | 68.817895149816 | | 2009 | 74.271991969705 | | 2008 | 76.4993221113 | | 2007 | 73.661440090345 | | 2006 | 70.621017083269 | | 2005 | 70.953861100808 | | 2004 | 71.468753975566 | | 2003 | 72.577403279522 | | 2002 | 71.325887240976 | | 2001 | 71.184408730612 | | 2000 | 72.875787395335 | | 1999 | 75.433437848488 | | 1998 | 78.512646218876 | | 1997 | 79.899752250313 | | 1996 | 82.794556602803 | | 1995 | 81.799713401954 |
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