| Year | Value | | 2022 | 77.805178297185 | | 2021 | 77.677275218495 | | 2020 | 77.559828419931 | | 2019 | 77.723839443869 | | 2018 | 77.343072317294 | | 2017 | 76.585174782418 | | 2016 | 75.971150326595 | | 2015 | 77.462247021832 | | 2014 | 78.725372030025 | | 2013 | 76.984929770425 | | 2012 | 75.166395604696 | | 2011 | 73.27901733427 | | 2010 | 71.21875196776 | | 2009 | 68.73757370809 | | 2008 | 67.858053959904 | | 2007 | 66.452326942778 | | 2006 | 64.590092190012 | | 2005 | 63.299284084343 | | 2004 | 63.700519792083 | | 2003 | 62.629906293749 | | 2002 | 61.899133999916 | | 2001 | 61.307265204622 | | 2000 | 60.845764034692 | | 1999 | 60.255594749321 | | 1998 | 59.674812555444 | | 1997 | 59.067178943875 | | 1996 | 58.572520209671 | | 1995 | 58.182278766044 | | 1994 | 57.429330047382 | | 1993 | 57.194250087651 | | 1992 | 57.062397164916 | | 1991 | 56.919946839057 |
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