| Year | Value | | 2022 | 70.676608895127 | | 2021 | 70.585647121872 | | 2020 | 70.69868682044 | | 2019 | 70.552728342256 | | 2018 | 70.256002407504 | | 2017 | 70.296530952502 | | 2016 | 70.365414811079 | | 2015 | 68.442235645067 | | 2014 | 67.632210777869 | | 2013 | 67.503909194211 | | 2012 | 67.480468457855 | | 2011 | 66.580511020794 | | 2010 | 66.503058452324 | | 2009 | 65.694832072375 | | 2008 | 65.193780203576 | | 2007 | 63.840724317421 | | 2006 | 64.146898534389 | | 2005 | 62.660652885786 | | 2004 | 61.385517772599 | | 2003 | 61.676441314955 | | 2002 | 61.903381099004 | | 2001 | 61.889183814794 | | 2000 | 61.302230960682 | | 1999 | 61.28030482754 | | 1998 | 60.910726819678 | | 1997 | 60.748414163851 | | 1996 | 60.234100573336 | | 1995 | 59.737061884751 | | 1994 | 59.465830418288 | | 1993 | 59.138459021707 | | 1992 | 58.945468417417 | | 1991 | 58.645369121776 |
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