Year | Value | 2022 | 49.535709809481 | 2021 | 49.555062738648 | 2020 | 49.57542809854 | 2019 | 49.595974638271 | 2018 | 49.614321864375 | 2017 | 49.630870886229 | 2016 | 49.647190286143 | 2015 | 49.661943189341 | 2014 | 49.674965474985 | 2013 | 49.686732729077 | 2012 | 49.696241959397 | 2011 | 49.704479827436 | 2010 | 49.688129896941 | 2009 | 49.668891186786 | 2008 | 49.671575051798 | 2007 | 49.673553040891 | 2006 | 49.674907578957 | 2005 | 49.675303723702 | 2004 | 49.67089732521 | 2003 | 49.664234255856 | 2002 | 49.658536709266 | 2001 | 49.651128419517 | 2000 | 49.642180682936 | 1999 | 49.631907453105 | 1998 | 49.619409554471 | 1997 | 49.603975756939 | 1996 | 49.587064976894 | 1995 | 49.568419611827 | 1994 | 49.546098224026 | 1993 | 49.522266721482 | 1992 | 49.498569204167 | 1991 | 49.474947477765 | 1990 | 49.447181658176 | 1989 | 49.415837861159 | 1988 | 49.385285898679 | 1987 | 49.353929852256 | 1986 | 49.32317108273 | 1985 | 49.2913421884 | 1984 | 49.254942701978 | 1983 | 49.216646472946 | 1982 | 49.179064407001 | 1981 | 49.1417915047 | 1980 | 49.104446580608 | 1979 | 49.069191425583 | 1978 | 49.037802466057 | 1977 | 49.00792230852 | 1976 | 48.978408537779 | 1975 | 48.95062210219 | 1974 | 48.924811336582 | 1973 | 48.900906954668 | 1972 | 48.878957585403 | 1971 | 48.858252823973 | 1970 | 48.838235759095 | 1969 | 48.819050950672 | 1968 | 48.801640937119 | 1967 | 48.785620373604 | 1966 | 48.77091369552 | 1965 | 48.757752059495 | 1964 | 48.745850261739 | 1963 | 48.73072052709 | 1962 | 48.717917058484 | 1961 | 48.711475460976 | 1960 | 48.706134285397 |
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