Year | Value | 2021 | 58.559231358337 | 2020 | 50.323247417526 | 2019 | 40.140373117122 | 2018 | 39.249165915598 | 2016 | 38.489440579748 | 2015 | 37.868867419314 | 2014 | 36.496651324112 | 2013 | 40.06185328898 | 2012 | 28.444716023883 | 2011 | 28.131976300687 | 2010 | 26.900845543727 | 2009 | 26.779195203645 | 2008 | 22.450217262329 | 2007 | 22.993466831918 | 2006 | 24.380659149465 | 2005 | 25.458128278077 | 2004 | 24.396399800871 | 2003 | 27.046018372081 | 2002 | 30.070356272157 | 2001 | 24.578334035859 | 2000 | 21.96458651392 | 1999 | 20.00577891556 | 1998 | 10.669857385421 | 1997 | 4.6415204094847 | 1996 | 3.6734974574247 | 1995 | 4.6100947123184 | 1994 | 5.6932197371167 | 1993 | 8.1862435367004 | 1992 | 10.878995158747 | 1991 | 13.365567336276 | 1990 | 18.447753850148 |
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