Year | Value | 2022 | 49.877659637439 | 2021 | 49.855309947945 | 2020 | 49.834513066474 | 2019 | 49.809715913916 | 2018 | 49.78115606689 | 2017 | 49.752053643304 | 2016 | 49.716748688474 | 2015 | 49.679286813396 | 2014 | 49.64303726192 | 2013 | 49.604396508926 | 2012 | 49.565127251911 | 2011 | 49.525955900125 | 2010 | 49.48676015171 | 2009 | 49.45951242711 | 2008 | 49.443255671549 | 2007 | 49.425093746364 | 2006 | 49.403819658356 | 2005 | 49.379889319888 | 2004 | 49.357048362443 | 2003 | 49.33628663634 | 2002 | 49.316051601045 | 2001 | 49.29812237355 | 2000 | 49.280949779286 | 1999 | 49.261288789888 | 1998 | 49.242082465571 | 1997 | 49.227036174258 | 1996 | 49.213433457568 | 1995 | 49.20344736576 | 1994 | 49.201259489755 | 1993 | 49.203836256987 | 1992 | 49.213576672312 | 1991 | 49.2324611982 | 1990 | 49.257211881779 | 1989 | 49.286617630736 | 1988 | 49.321536642004 | 1987 | 49.366232777202 | 1986 | 49.418134029271 | 1985 | 49.468845460603 | 1984 | 49.518457317033 | 1983 | 49.567351152637 | 1982 | 49.613251408548 | 1981 | 49.660089945752 | 1980 | 49.710303454995 | 1979 | 49.758840891031 | 1978 | 49.801827954576 | 1977 | 49.840965681682 | 1976 | 49.879934950348 | 1975 | 49.913874677325 | 1974 | 49.940128098023 | 1973 | 49.961484304076 | 1972 | 49.980486710777 | 1971 | 50.000380973457 | 1970 | 50.021067606551 | 1969 | 50.044357446614 | 1968 | 50.071307548395 | 1967 | 50.102473296573 | 1966 | 50.140222532612 | 1965 | 50.183517090426 | 1964 | 50.230678642971 | 1963 | 50.284250284667 | 1962 | 50.345489879372 | 1961 | 50.413221473701 | 1960 | 50.488133244526 |
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