Year | Value | 2022 | 49.506612983895 | 2021 | 49.50626347545 | 2020 | 49.50924850573 | 2019 | 49.50969393137 | 2018 | 49.505023191547 | 2017 | 49.496627095785 | 2016 | 49.48639905143 | 2015 | 49.477053054802 | 2014 | 49.465118365487 | 2013 | 49.45259029096 | 2012 | 49.443210174206 | 2011 | 49.43040755054 | 2010 | 49.412234119105 | 2009 | 49.393348860684 | 2008 | 49.377178977215 | 2007 | 49.366351197086 | 2006 | 49.355770550189 | 2005 | 49.344504182324 | 2004 | 49.334354759843 | 2003 | 49.32237868044 | 2002 | 49.316793430904 | 2001 | 49.316651197731 | 2000 | 49.31309500039 | 1999 | 49.306980915166 | 1998 | 49.300468810438 | 1997 | 49.296072414175 | 1996 | 49.2892694703 | 1995 | 49.27760772229 | 1994 | 49.261262298812 | 1993 | 49.24803774858 | 1992 | 49.24055250365 | 1991 | 49.23060676777 | 1990 | 49.217733368544 | 1989 | 49.204632651994 | 1988 | 49.193639590958 | 1987 | 49.18472640053 | 1986 | 49.179194340531 | 1985 | 49.177045998971 | 1984 | 49.183310233571 | 1983 | 49.196935017868 | 1982 | 49.214691183366 | 1981 | 49.236172515571 | 1980 | 49.25655320396 | 1979 | 49.275971469686 | 1978 | 49.296597477039 | 1977 | 49.322035294144 | 1976 | 49.353275626024 | 1975 | 49.387054764191 | 1974 | 49.431192930195 | 1973 | 49.485076050171 | 1972 | 49.540564147248 | 1971 | 49.599645037135 | 1970 | 49.64918344542 | 1969 | 49.690512468714 | 1968 | 49.734752836405 | 1967 | 49.776403002608 | 1966 | 49.815003412918 | 1965 | 49.854216948379 | 1964 | 49.896581922084 | 1963 | 49.940008941202 | 1962 | 49.983256708413 | 1961 | 50.025422311375 | 1960 | 50.081622648423 |
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