Year | Value | 2021 | 23.045 | 2020 | 23.139 | 2019 | 23.424 | 2018 | 23.625 | 2017 | 24.015 | 2016 | 24.543 | 2015 | 25.171 | 2014 | 25.68 | 2013 | 26.104 | 2012 | 26.505 | 2011 | 26.943 | 2010 | 27.266 | 2009 | 27.63 | 2008 | 27.993 | 2007 | 28.277 | 2006 | 28.731 | 2005 | 29.13 | 2004 | 29.347 | 2003 | 29.248 | 2002 | 28.71 | 2001 | 28.257 | 2000 | 28.378 | 1999 | 28.875 | 1998 | 29.343 | 1997 | 29.285 | 1996 | 29.834 | 1995 | 30.085 | 1994 | 30.488 | 1993 | 30.806 | 1992 | 30.936 | 1991 | 30.867 | 1990 | 30.655 | 1989 | 30.638 | 1988 | 30.766 | 1987 | 31.057 | 1986 | 31.915 | 1985 | 32.87 | 1984 | 33.778 | 1983 | 34.494 | 1982 | 34.916 | 1981 | 35.077 | 1980 | 34.991 | 1979 | 34.674 | 1978 | 34.146 | 1977 | 33.59 | 1976 | 33.37 | 1975 | 33.27 | 1974 | 33.355 | 1973 | 33.663 | 1972 | 34.287 | 1971 | 35.26 | 1970 | 36.522 | 1969 | 38.021 | 1968 | 39.657 | 1967 | 41.26 | 1966 | 41.505 | 1965 | 42.113 | 1964 | 42.778 | 1963 | 43.282 | 1962 | 43.739 | 1961 | 44.232 | 1960 | 44.74 |
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