| Year | Value | | 2020 | 60.280373324788 | | 2019 | 50.271810744228 | | 2018 | 47.444216906529 | | 2017 | 45.074385213917 | | 2016 | 46.458466870983 | | 2015 | 47.276558512695 | | 2014 | 41.285000740618 | | 2013 | 40.088494375646 | | 2012 | 41.028234748874 | | 2011 | 43.207416877579 | | 2010 | 42.466638814169 | | 2009 | 47.695501441191 | | 2008 | 55.86657946583 | | 2007 | 57.559981877004 | | 2006 | 68.460704592018 | | 2005 | 76.114459708002 | | 2004 | 85.425594123742 | | 2003 | 105.60278085225 | | 2002 | 95.267860720411 | | 2001 | 40.643334859651 | | 1994 | 24.53018807181 | | 1993 | 21.87914303713 | | 1992 | 23.604777319411 | | 1991 | 24.590575759141 | | 1990 | 31.595963036401 |
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