| Year | Value | | 2022 | 76.172662976208 | | 2021 | 72.21979374911 | | 2020 | 72.3156707026 | | 2019 | 71.434607011916 | | 2018 | 69.738366715027 | | 2017 | 69.6220688576 | | 2016 | 69.458690270765 | | 2015 | 68.639432010428 | | 2014 | 67.627200622425 | | 2013 | 68.054012213769 | | 2012 | 66.811348114259 | | 2011 | 66.542775774813 | | 2010 | 67.579920055715 | | 2009 | 66.498879193019 | | 2008 | 64.564977636174 | | 2007 | 59.24817582937 | | 2006 | 58.487290821956 | | 2005 | 58.832976086811 | | 2004 | 57.5972446587 | | 2003 | 56.411490071188 | | 2002 | 58.501176285387 | | 2001 | 61.051742957243 | | 2000 | 65.481377942563 | | 1999 | 65.780077177763 | | 1998 | 65.590315595366 | | 1997 | 65.521296103749 | | 1996 | 65.702127826004 | | 1995 | 65.888620172594 | | 1994 | 65.925182773894 | | 1993 | 65.723855018969 | | 1992 | 65.802663311314 | | 1991 | 65.855077522762 |
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