Year | Value | 2021 | 19.345 | 2020 | 19.628 | 2019 | 19.962 | 2018 | 20.187 | 2017 | 20.55 | 2016 | 21.05 | 2015 | 21.45 | 2014 | 21.683 | 2013 | 21.835 | 2012 | 21.925 | 2011 | 22.126 | 2010 | 22.664 | 2009 | 23.172 | 2008 | 23.614 | 2007 | 23.859 | 2006 | 24.051 | 2005 | 23.796 | 2004 | 24.067 | 2003 | 24.242 | 2002 | 24.267 | 2001 | 24.289 | 2000 | 24.34 | 1999 | 24.562 | 1998 | 24.813 | 1997 | 25.386 | 1996 | 26.001 | 1995 | 26.266 | 1994 | 26.588 | 1993 | 27.249 | 1992 | 27.946 | 1991 | 28.584 | 1990 | 29.177 | 1989 | 29.538 | 1988 | 30.049 | 1987 | 30.653 | 1986 | 30.956 | 1985 | 32.001 | 1984 | 32.732 | 1983 | 33.121 | 1982 | 33.522 | 1981 | 33.851 | 1980 | 34.038 | 1979 | 34.058 | 1978 | 33.846 | 1977 | 33.4 | 1976 | 32.914 | 1975 | 32.166 | 1974 | 31.239 | 1973 | 31.471 | 1972 | 32.21 | 1971 | 33.401 | 1970 | 34.142 | 1969 | 35.042 | 1968 | 35.756 | 1967 | 36.491 | 1966 | 38.023 | 1965 | 39.117 | 1964 | 40.355 | 1963 | 41.773 | 1962 | 42.897 | 1961 | 42.755 | 1960 | 44.194 |
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