Year | Value | 2021 | 17.622 | 2020 | 17.833 | 2019 | 18.042 | 2018 | 18.092 | 2017 | 18.269 | 2016 | 18.5 | 2015 | 18.808 | 2014 | 19.248 | 2013 | 19.71 | 2012 | 20.225 | 2011 | 20.75 | 2010 | 21.066 | 2009 | 21.417 | 2008 | 21.655 | 2007 | 22.026 | 2006 | 22.274 | 2005 | 22.334 | 2004 | 22.278 | 2003 | 22.209 | 2002 | 22.481 | 2001 | 22.908 | 2000 | 23.719 | 1999 | 24.202 | 1998 | 24.789 | 1997 | 25.455 | 1996 | 26.164 | 1995 | 26.908 | 1994 | 27.692 | 1993 | 28.49 | 1992 | 29.287 | 1991 | 30.152 | 1990 | 30.9 | 1989 | 31.622 | 1988 | 32.332 | 1987 | 32.892 | 1986 | 33.482 | 1985 | 33.993 | 1984 | 34.455 | 1983 | 34.953 | 1982 | 35.42 | 1981 | 35.946 | 1980 | 36.546 | 1979 | 37.159 | 1978 | 37.723 | 1977 | 38.336 | 1976 | 38.895 | 1975 | 39.466 | 1974 | 40.114 | 1973 | 40.733 | 1972 | 41.342 | 1971 | 41.917 | 1970 | 42.439 | 1969 | 42.901 | 1968 | 43.407 | 1967 | 44.001 | 1966 | 44.439 | 1965 | 44.928 | 1964 | 45.395 | 1963 | 45.791 | 1962 | 46.216 | 1961 | 46.594 | 1960 | 46.883 |
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