| Year | Value | | 2022 | 55.678532706903 | | 2021 | 59.146321684673 | | 2020 | 55.731443026231 | | 2019 | 60.816228984648 | | 2018 | 62.608311195792 | | 2017 | 63.456812407926 | | 2016 | 64.201033882731 | | 2015 | 66.271051297972 | | 2014 | 67.330824236977 | | 2013 | 67.722482491347 | | 2012 | 68.020044609154 | | 2011 | 67.996080701335 | | 2010 | 65.904453530603 | | 2009 | 64.67388007943 | | 2008 | 66.069936326022 | | 2007 | 65.319925809365 | | 2006 | 62.965929595521 | | 2005 | 63.406610398909 | | 2004 | 63.854700075564 | | 2003 | 64.118582948547 | | 2002 | 64.537752834478 | | 2001 | 65.096984910524 | | 2000 | 65.795485130434 | | 1999 | 66.336870696568 | | 1998 | 66.507634283215 | | 1997 | 66.873109100727 | | 1996 | 66.862800860753 | | 1995 | 66.909816962669 | | 1994 | 66.776049513045 | | 1993 | 66.697012469619 | | 1992 | 66.445834152622 | | 1991 | 66.392947319464 |
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