Year | Value | 2022 | 18.7 | 2021 | 18.984 | 2020 | 19.269 | 2019 | 19.556 | 2018 | 19.844 | 2017 | 20.133 | 2016 | 20.423 | 2015 | 20.715 | 2014 | 21.007 | 2013 | 21.301 | 2012 | 21.595 | 2011 | 21.889 | 2010 | 22.185 | 2009 | 22.48 | 2008 | 22.778 | 2007 | 23.08 | 2006 | 23.384 | 2005 | 23.692 | 2004 | 24.003 | 2003 | 24.318 | 2002 | 24.635 | 2001 | 24.955 | 2000 | 25.278 | 1999 | 25.559 | 1998 | 25.814 | 1997 | 26.071 | 1996 | 26.33 | 1995 | 26.632 | 1994 | 27.015 | 1993 | 27.402 | 1992 | 27.791 | 1991 | 28.184 | 1990 | 28.581 | 1989 | 29.044 | 1988 | 29.538 | 1987 | 30.037 | 1986 | 30.541 | 1985 | 31.05 | 1984 | 31.563 | 1983 | 32.081 | 1982 | 32.604 | 1981 | 33.13 | 1980 | 33.661 | 1979 | 34.354 | 1978 | 35.066 | 1977 | 35.785 | 1976 | 36.509 | 1975 | 37.241 | 1974 | 37.978 | 1973 | 38.721 | 1972 | 39.468 | 1971 | 40.221 | 1970 | 40.979 | 1969 | 41.771 | 1968 | 42.589 | 1967 | 43.413 | 1966 | 44.239 | 1965 | 45.069 | 1964 | 45.9 | 1963 | 46.735 | 1962 | 47.572 | 1961 | 48.41 | 1960 | 49.247 |
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