| Year | Value | | 2022 | 62.683589144574 | | 2021 | 61.492879038539 | | 2020 | 62.11345995932 | | 2019 | 62.547943131478 | | 2018 | 62.419187455519 | | 2017 | 62.815303006879 | | 2016 | 63.200060732965 | | 2015 | 63.548518050331 | | 2014 | 63.977853215245 | | 2013 | 63.603835458394 | | 2012 | 63.428555703549 | | 2011 | 62.415103982009 | | 2010 | 62.244549545244 | | 2009 | 61.936392797865 | | 2008 | 62.148619154946 | | 2007 | 61.948837885649 | | 2006 | 60.826451694648 | | 2005 | 60.184402064558 | | 2004 | 59.691685606088 | | 2003 | 59.195695859989 | | 2002 | 59.093156694157 | | 2001 | 59.380206031484 | | 2000 | 59.661180542674 | | 1999 | 59.089189992487 | | 1998 | 59.260247249071 | | 1997 | 58.767551387569 | | 1996 | 59.122566728017 | | 1995 | 58.374075105436 | | 1994 | 58.023700655441 | | 1993 | 57.810725274816 | | 1992 | 58.078279890308 | | 1991 | 58.302994835779 |
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