Year | Value | 2021 | 23.576 | 2020 | 24.195 | 2019 | 24.887 | 2018 | 25.328 | 2017 | 25.672 | 2016 | 26.13 | 2015 | 26.409 | 2014 | 26.771 | 2013 | 27.097 | 2012 | 27.407 | 2011 | 27.596 | 2010 | 27.898 | 2009 | 28.175 | 2008 | 28.406 | 2007 | 28.563 | 2006 | 28.635 | 2005 | 28.404 | 2004 | 28.141 | 2003 | 28.178 | 2002 | 28.477 | 2001 | 28.906 | 2000 | 28.961 | 1999 | 28.885 | 1998 | 28.971 | 1997 | 29.115 | 1996 | 29.865 | 1995 | 31.042 | 1994 | 32.248 | 1993 | 32.808 | 1992 | 33.172 | 1991 | 33.512 | 1990 | 34.35 | 1989 | 35.304 | 1988 | 36.524 | 1987 | 37.793 | 1986 | 39.015 | 1985 | 39.817 | 1984 | 40.588 | 1983 | 41.451 | 1982 | 42.536 | 1981 | 43.684 | 1980 | 44.499 | 1979 | 45.147 | 1978 | 45.689 | 1977 | 46.041 | 1976 | 46.425 | 1975 | 46.383 | 1974 | 46.293 | 1973 | 46.126 | 1972 | 45.978 | 1971 | 45.764 | 1970 | 45.698 | 1969 | 45.633 | 1968 | 45.693 | 1967 | 45.713 | 1966 | 45.849 | 1965 | 45.942 | 1964 | 46.24 | 1963 | 46.186 | 1962 | 46.094 | 1961 | 46.586 | 1960 | 47.09 |
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