Year | Value | 2022 | 49.560740171077 | 2021 | 49.551912493788 | 2020 | 49.540174832025 | 2019 | 49.532875587288 | 2018 | 49.525484191046 | 2017 | 49.506606866011 | 2016 | 49.490074617434 | 2015 | 49.467589417373 | 2014 | 49.475451665853 | 2013 | 49.516303930935 | 2012 | 49.540962416887 | 2011 | 49.592133437753 | 2010 | 49.665947263672 | 2009 | 49.761944552104 | 2008 | 49.892282620219 | 2007 | 50.006582819438 | 2006 | 50.012491717448 | 2005 | 49.89561333354 | 2004 | 49.762546894136 | 2003 | 49.682332985155 | 2002 | 49.671773159354 | 2001 | 49.692297085049 | 2000 | 49.68585415036 | 1999 | 49.659158603752 | 1998 | 49.641949108196 | 1997 | 49.631004216859 | 1996 | 49.631244718204 | 1995 | 49.641428564245 | 1994 | 49.676799278979 | 1993 | 49.711284090589 | 1992 | 49.717475534716 | 1991 | 49.707330365027 | 1990 | 49.686059516138 | 1989 | 49.683864274079 | 1988 | 49.748944405851 | 1987 | 49.852577055526 | 1986 | 49.930667534401 | 1985 | 49.98834777762 | 1984 | 50.03536305931 | 1983 | 50.077759154229 | 1982 | 50.125955751197 | 1981 | 50.173979590794 | 1980 | 50.20347132309 | 1979 | 50.224827843807 | 1978 | 50.242272817616 | 1977 | 50.239564046896 | 1976 | 50.226888971171 | 1975 | 50.214904182153 | 1974 | 50.204736247946 | 1973 | 50.198153312369 | 1972 | 50.190710146457 | 1971 | 50.182208711061 | 1970 | 50.184348849092 | 1969 | 50.195839549374 | 1968 | 50.203214671599 | 1967 | 50.204232424304 | 1966 | 50.205946767408 | 1965 | 50.212610358782 | 1964 | 50.220762688568 | 1963 | 50.22377127633 | 1962 | 50.227349721852 | 1961 | 50.24091513909 | 1960 | 50.279449049062 |
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