Year | Value | 2021 | 36.795 | 2020 | 37.252 | 2019 | 37.667 | 2018 | 38.062 | 2017 | 38.343 | 2016 | 38.709 | 2015 | 39.422 | 2014 | 40.154 | 2013 | 40.943 | 2012 | 41.743 | 2011 | 42.434 | 2010 | 43.068 | 2009 | 43.544 | 2008 | 43.934 | 2007 | 44.688 | 2006 | 45.363 | 2005 | 45.989 | 2004 | 46.68 | 2003 | 47.115 | 2002 | 47.774 | 2001 | 48.251 | 2000 | 48.593 | 1999 | 49.081 | 1998 | 49.335 | 1997 | 49.91 | 1996 | 50.206 | 1995 | 50.856 | 1994 | 50.898 | 1993 | 51.152 | 1992 | 51.281 | 1991 | 51.174 | 1990 | 51.372 | 1989 | 51.313 | 1988 | 51.225 | 1987 | 51.09 | 1986 | 50.562 | 1985 | 49.923 | 1984 | 49.199 | 1983 | 48.844 | 1982 | 48.708 | 1981 | 48.849 | 1980 | 48.792 | 1979 | 48.842 | 1978 | 48.703 | 1977 | 48.758 | 1976 | 48.879 | 1975 | 48.884 | 1974 | 48.704 | 1973 | 48.774 | 1972 | 48.982 | 1971 | 49.054 | 1970 | 48.965 | 1969 | 48.822 | 1968 | 48.884 | 1967 | 48.578 | 1966 | 48.35 | 1965 | 48.126 | 1964 | 48.018 | 1963 | 48.034 | 1962 | 48.155 | 1961 | 48.374 | 1960 | 48.67 |
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