Year | Value | 2021 | 32.383 | 2020 | 32.78 | 2019 | 33.123 | 2018 | 32.996 | 2017 | 33.059 | 2016 | 33.315 | 2015 | 33.428 | 2014 | 33.554 | 2013 | 33.938 | 2012 | 34.845 | 2011 | 35.846 | 2010 | 36.528 | 2009 | 37.293 | 2008 | 38.46 | 2007 | 39.51 | 2006 | 40.232 | 2005 | 40.997 | 2004 | 41.657 | 2003 | 42.306 | 2002 | 43.39 | 2001 | 44.029 | 2000 | 44.501 | 1999 | 45.269 | 1998 | 45.842 | 1997 | 46.776 | 1996 | 47.371 | 1995 | 47.648 | 1994 | 48.191 | 1993 | 48.723 | 1992 | 49.056 | 1991 | 49.797 | 1990 | 50.052 | 1989 | 50.003 | 1988 | 50.298 | 1987 | 50.732 | 1986 | 51.027 | 1985 | 51.019 | 1984 | 50.699 | 1983 | 50.183 | 1982 | 49.968 | 1981 | 49.863 | 1980 | 49.835 | 1979 | 49.836 | 1978 | 49.803 | 1977 | 49.886 | 1976 | 49.686 | 1975 | 49.589 | 1974 | 49.555 | 1973 | 49.423 | 1972 | 49.538 | 1971 | 49.521 | 1970 | 49.418 | 1969 | 49.304 | 1968 | 48.838 | 1967 | 48.659 | 1966 | 48.457 | 1965 | 48.267 | 1964 | 48.048 | 1963 | 47.813 | 1962 | 47.693 | 1961 | 47.592 | 1960 | 47.462 |
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