Year | Value | 2022 | 18.696 | 2021 | 18.944 | 2020 | 19.19 | 2019 | 19.435 | 2018 | 19.679 | 2017 | 19.92 | 2016 | 20.16 | 2015 | 20.398 | 2014 | 20.634 | 2013 | 20.867 | 2012 | 21.098 | 2011 | 21.327 | 2010 | 21.558 | 2009 | 21.79 | 2008 | 22.024 | 2007 | 22.26 | 2006 | 22.498 | 2005 | 22.737 | 2004 | 22.978 | 2003 | 23.222 | 2002 | 23.467 | 2001 | 23.657 | 2000 | 23.738 | 1999 | 23.819 | 1998 | 23.9 | 1997 | 23.981 | 1996 | 24.062 | 1995 | 24.144 | 1994 | 24.226 | 1993 | 24.308 | 1992 | 24.39 | 1991 | 24.472 | 1990 | 24.649 | 1989 | 24.874 | 1988 | 25.1 | 1987 | 25.327 | 1986 | 25.556 | 1985 | 25.787 | 1984 | 26.018 | 1983 | 26.251 | 1982 | 26.485 | 1981 | 26.721 | 1980 | 27.211 | 1979 | 27.838 | 1978 | 28.473 | 1977 | 29.117 | 1976 | 29.769 | 1975 | 30.43 | 1974 | 31.099 | 1973 | 31.776 | 1972 | 32.459 | 1971 | 33.152 | 1970 | 33.962 | 1969 | 34.892 | 1968 | 35.832 | 1967 | 36.786 | 1966 | 37.749 | 1965 | 38.722 | 1964 | 39.702 | 1963 | 40.694 | 1962 | 41.692 | 1961 | 42.697 | 1960 | 43.433 |
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