Year | Value | 2022 | 50.269819325982 | 2021 | 50.264476023759 | 2020 | 50.257895098418 | 2019 | 50.248304823407 | 2018 | 50.23676227174 | 2017 | 50.222207507009 | 2016 | 50.204741877219 | 2015 | 50.185281355623 | 2014 | 50.164144776695 | 2013 | 50.141164885061 | 2012 | 50.115979837251 | 2011 | 50.089069375427 | 2010 | 50.061299283079 | 2009 | 50.034819986297 | 2008 | 50.007971095778 | 2007 | 49.980363906827 | 2006 | 49.953628043798 | 2005 | 49.927227008488 | 2004 | 49.902555479408 | 2003 | 49.879810020327 | 2002 | 49.859643156974 | 2001 | 49.839954942506 | 2000 | 49.822415378487 | 1999 | 49.805615967819 | 1998 | 49.788962072391 | 1997 | 49.775179366583 | 1996 | 49.762105750421 | 1995 | 49.748853037901 | 1994 | 49.735450123295 | 1993 | 49.719840564615 | 1992 | 49.704484831423 | 1991 | 49.692184506349 | 1990 | 49.683238702696 | 1989 | 49.677454667096 | 1988 | 49.673976712231 | 1987 | 49.670670228188 | 1986 | 49.666508691999 | 1985 | 49.661142727666 | 1984 | 49.653986518345 | 1983 | 49.643370588508 | 1982 | 49.631682544786 | 1981 | 49.618967382296 | 1980 | 49.602517168115 | 1979 | 49.583122075589 | 1978 | 49.563080121779 | 1977 | 49.542314262841 | 1976 | 49.521514621911 | 1975 | 49.500042435131 | 1974 | 49.478418257095 | 1973 | 49.459138762705 | 1972 | 49.441713748292 | 1971 | 49.425571770779 | 1970 | 49.409547630067 | 1969 | 49.392261962588 | 1968 | 49.375430714182 | 1967 | 49.361014202182 | 1966 | 49.347873896788 | 1965 | 49.336078523574 | 1964 | 49.326602175723 | 1963 | 49.318562765986 | 1962 | 49.311623051005 | 1961 | 49.307238317167 | 1960 | 49.306180879235 |
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