Year | Value | 2022 | 50.324919040265 | 2021 | 50.31908508498 | 2020 | 50.313159926218 | 2019 | 50.304128637423 | 2018 | 50.285502006325 | 2017 | 50.263497105212 | 2016 | 50.237469854967 | 2015 | 50.204990272831 | 2014 | 50.165114405499 | 2013 | 50.116559599145 | 2012 | 50.059097212778 | 2011 | 49.994932444801 | 2010 | 49.922649292245 | 2009 | 49.838537256534 | 2008 | 49.747789204829 | 2007 | 49.658470163907 | 2006 | 49.571805095264 | 2005 | 49.48708679065 | 2004 | 49.40466423298 | 2003 | 49.323281316785 | 2002 | 49.241663743139 | 2001 | 49.158361692732 | 2000 | 49.092889874985 | 1999 | 49.12455075599 | 1998 | 49.219570865083 | 1997 | 49.286365741501 | 1996 | 49.289184173902 | 1995 | 49.236761670086 | 1994 | 49.191909776597 | 1993 | 49.204747415355 | 1992 | 49.22773349212 | 1991 | 49.184890105045 | 1990 | 49.102745364406 | 1989 | 49.025707345205 | 1988 | 49.091081995757 | 1987 | 49.303003279426 | 1986 | 49.526695081009 | 1985 | 49.742972897469 | 1984 | 49.834827280091 | 1983 | 49.802726432931 | 1982 | 49.768562446306 | 1981 | 49.73292042651 | 1980 | 49.696129353566 | 1979 | 49.658833335622 | 1978 | 49.619890867585 | 1977 | 49.578829114693 | 1976 | 49.537097637558 | 1975 | 49.494547151524 | 1974 | 49.452447451831 | 1973 | 49.410966389798 | 1972 | 49.372245092771 | 1971 | 49.336527584114 | 1970 | 49.30132418137 | 1969 | 49.266445827962 | 1968 | 49.230304934928 | 1967 | 49.193597398708 | 1966 | 49.157561947447 | 1965 | 49.119310403243 | 1964 | 49.079350634472 | 1963 | 49.039330177958 | 1962 | 48.998701895477 | 1961 | 48.957394523434 | 1960 | 48.916365539833 |
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