Year | Value | 2021 | 36.598 | 2020 | 36.974 | 2019 | 37.345 | 2018 | 37.753 | 2017 | 38.127 | 2016 | 38.437 | 2015 | 38.797 | 2014 | 39.254 | 2013 | 40.548 | 2012 | 41.079 | 2011 | 41.605 | 2010 | 42.013 | 2009 | 41.921 | 2008 | 41.61 | 2007 | 41.105 | 2006 | 41.422 | 2005 | 41.867 | 2004 | 42.315 | 2003 | 42.899 | 2002 | 43.037 | 2001 | 43.395 | 2000 | 43.734 | 1999 | 43.994 | 1998 | 44.198 | 1997 | 44.441 | 1996 | 44.305 | 1995 | 44.546 | 1994 | 44.944 | 1993 | 45.306 | 1992 | 45.563 | 1991 | 45.967 | 1990 | 46.385 | 1989 | 46.735 | 1988 | 46.89 | 1987 | 47.109 | 1986 | 47.202 | 1985 | 47.387 | 1984 | 47.631 | 1983 | 47.655 | 1982 | 47.833 | 1981 | 48.312 | 1980 | 48.718 | 1979 | 48.631 | 1978 | 48.21 | 1977 | 47.815 | 1976 | 47.487 | 1975 | 47.213 | 1974 | 46.978 | 1973 | 46.813 | 1972 | 46.757 | 1971 | 46.817 | 1970 | 47.057 | 1969 | 47.224 | 1968 | 47.217 | 1967 | 47.258 | 1966 | 47.368 | 1965 | 47.435 | 1964 | 47.557 | 1963 | 47.694 | 1962 | 47.679 | 1961 | 47.483 | 1960 | 47.269 |
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