| Year | Value | | 2021 | 41.590722009069 | | 2020 | 41.590722009069 | | 2019 | 41.590722009069 | | 2018 | 41.590722009069 | | 2017 | 41.590722009069 | | 2016 | 41.590722009069 | | 2015 | 41.590722009069 | | 2014 | 41.590722009069 | | 2013 | 41.590722009069 | | 2012 | 41.590722009069 | | 2011 | 41.590722009069 | | 2010 | 41.590722009069 | | 2009 | 41.464269271015 | | 2008 | 41.337816532961 | | 2007 | 41.211363794908 | | 2006 | 41.084911056854 | | 2005 | 40.9584583188 | | 2004 | 40.832005580746 | | 2003 | 40.705552842693 | | 2002 | 40.579100104639 | | 2001 | 40.452647366585 | | 2000 | 40.326194628532 | | 1999 | 40.348839160839 | | 1998 | 40.272783216783 | | 1997 | 40.196727272727 | | 1996 | 40.120671328671 | | 1995 | 40.044615384615 | | 1994 | 39.968559440559 | | 1993 | 39.892503496504 | | 1992 | 39.816447552447 | | 1991 | 39.740391608392 | | 1990 | 39.664335664336 |
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