Year | Value | 2022 | 50.603075629593 | 2021 | 50.61335753491 | 2020 | 50.618926682758 | 2019 | 50.626378753684 | 2018 | 50.633094075468 | 2017 | 50.642163593378 | 2016 | 50.65322041585 | 2015 | 50.666209660906 | 2014 | 50.681688567205 | 2013 | 50.699085306656 | 2012 | 50.717267064993 | 2011 | 50.734971125971 | 2010 | 50.751845774306 | 2009 | 50.769007888413 | 2008 | 50.793852105584 | 2007 | 50.827156361282 | 2006 | 50.862267396292 | 2005 | 50.898384266117 | 2004 | 50.9344235629 | 2003 | 50.969548329213 | 2002 | 51.004765389403 | 2001 | 51.040158635338 | 2000 | 51.074041436009 | 1999 | 51.087020147135 | 1998 | 51.091670173372 | 1997 | 51.106865583634 | 1996 | 51.119538046686 | 1995 | 51.131119938947 | 1994 | 51.140052562246 | 1993 | 51.147060602457 | 1992 | 51.157809152241 | 1991 | 51.172567051333 | 1990 | 51.189296702551 | 1989 | 51.207527786675 | 1988 | 51.220612655263 | 1987 | 51.22675530167 | 1986 | 51.230138651364 | 1985 | 51.235554718553 | 1984 | 51.243513968555 | 1983 | 51.248840495954 | 1982 | 51.252832152658 | 1981 | 51.258378854066 | 1980 | 51.264130393536 | 1979 | 51.197053584653 | 1978 | 51.136028474763 | 1977 | 51.156623629173 | 1976 | 51.179136979725 | 1975 | 51.194359349244 | 1974 | 51.176015929689 | 1973 | 51.138721124933 | 1972 | 51.09321571605 | 1971 | 51.045012301061 | 1970 | 51.007379191353 | 1969 | 50.965664139961 | 1968 | 50.9143800616 | 1967 | 50.87193137393 | 1966 | 50.849828632281 | 1965 | 50.83250642975 | 1964 | 50.822308567662 | 1963 | 50.816398031825 | 1962 | 50.815565544906 | 1961 | 50.81798271143 | 1960 | 50.823933925254 |
|