| Year | Value | | 2023 | 71.70268622224 | | 2022 | 72.704129716299 | | 2021 | 72.124712150237 | | 2020 | 71.333002679209 | | 2019 | 72.197363294464 | | 2018 | 75.831647991255 | | 2017 | 79.172510484708 | | 2016 | 77.287818114289 | | 2015 | 80.444319676983 | | 2014 | 78.733472872237 | | 2013 | 76.708202648866 | | 2012 | 76.504515345119 | | 2011 | 72.345524335657 | | 2010 | 71.811367593083 | | 2009 | 71.599383127892 | | 2008 | 73.674154543884 | | 2007 | 75.597795071552 | | 2006 | 74.197948417095 | | 2005 | 73.604816595095 | | 2004 | 71.997265823234 | | 2003 | 71.801463468236 | | 2002 | 68.809836714275 | | 2001 | 65.382773078247 | | 2000 | 66.411898025334 | | 1999 | 61.449515449395 | | 1998 | 60.647696233819 | | 1997 | 60.650405668922 | | 1996 | 60.941078073726 | | 1995 | 59.678968507491 | | 1994 | 56.176441813404 | | 1993 | 55.731459001607 | | 1992 | 50.820959100061 | | 1991 | 48.229235535239 | | 1990 | 54.005242470044 |
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