| Year | Value | | 2021 | 46.922216898259 | | 2020 | 46.994570424784 | | 2019 | 47.508783136378 | | 2018 | 47.054127414977 | | 2017 | 46.859085902205 | | 2016 | 47.155263241914 | | 2015 | 47.979249800479 | | 2014 | 47.125299281724 | | 2013 | 46.133226964499 | | 2012 | 45.3489485273 | | 2011 | 44.769760985417 | | 2010 | 44.23294774631 | | 2009 | 42.903869166334 | | 2008 | 42.634224172318 | | 2007 | 43.010529674537 | | 2006 | 44.522973835354 | | 2005 | 45.2616464582 | | 2004 | 41.549138481174 | | 2003 | 40.53924696873 | | 2002 | 46.027440970006 | | 2001 | 46.202935545629 | | 2000 | 54.530950861519 | | 1999 | 55.775366943204 | | 1998 | 54.642629227824 | | 1997 | 54.514996809189 | | 1996 | 54.419272495214 | | 1995 | 54.403318442884 | | 1994 | 49.872367581366 | | 1993 | 53.174856413529 | | 1992 | 54.068283343969 |
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