Year | Value | 2022 | 49.540879241522 | 2021 | 49.539590545668 | 2020 | 49.535040584356 | 2019 | 49.529440992982 | 2018 | 49.522742209236 | 2017 | 49.511919727672 | 2016 | 49.496699446423 | 2015 | 49.4801030308 | 2014 | 49.463885129695 | 2013 | 49.444281077931 | 2012 | 49.420794250334 | 2011 | 49.397619128897 | 2010 | 49.376382173779 | 2009 | 49.356421989219 | 2008 | 49.338197045029 | 2007 | 49.323368811362 | 2006 | 49.31198424555 | 2005 | 49.300489686897 | 2004 | 49.289616647357 | 2003 | 49.279699801723 | 2002 | 49.267520017161 | 2001 | 49.253607370207 | 2000 | 49.239614876524 | 1999 | 49.225307976154 | 1998 | 49.208589293463 | 1997 | 49.189398286581 | 1996 | 49.168409053234 | 1995 | 49.142968275145 | 1994 | 49.110012806563 | 1993 | 49.069275526093 | 1992 | 49.022391935144 | 1991 | 48.969826117764 | 1990 | 48.911747993026 | 1989 | 48.846865341011 | 1988 | 48.847837372451 | 1987 | 48.916120415065 | 1986 | 48.977799808378 | 1985 | 49.036754281871 | 1984 | 49.091682439088 | 1983 | 49.142496176435 | 1982 | 49.189746278408 | 1981 | 49.232577344052 | 1980 | 49.271351491825 | 1979 | 49.273616586363 | 1978 | 49.239581312146 | 1977 | 49.204575070731 | 1976 | 49.168839785826 | 1975 | 49.136378753326 | 1974 | 49.106197838838 | 1973 | 49.075072608252 | 1972 | 49.04499878456 | 1971 | 49.014985643212 | 1970 | 48.986250767682 | 1969 | 48.959854773675 | 1968 | 48.934008345116 | 1967 | 48.910914835503 | 1966 | 48.89017280212 | 1965 | 48.869086682533 | 1964 | 48.848619285089 | 1963 | 48.828943242661 | 1962 | 48.810624928649 | 1961 | 48.794653704489 | 1960 | 48.781874745639 |
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