Year | Value | 2021 | 8.718 | 2020 | 8.274 | 2019 | 8.203 | 2018 | 8.235 | 2017 | 8.326 | 2016 | 8.516 | 2015 | 8.685 | 2014 | 8.865 | 2013 | 8.999 | 2012 | 9.175 | 2011 | 9.313 | 2010 | 9.457 | 2009 | 9.553 | 2008 | 9.677 | 2007 | 9.819 | 2006 | 9.899 | 2005 | 9.997 | 2004 | 10.009 | 2003 | 10.174 | 2002 | 10.317 | 2001 | 10.292 | 2000 | 10.51 | 1999 | 10.513 | 1998 | 10.767 | 1997 | 10.819 | 1996 | 10.927 | 1995 | 11.159 | 1994 | 11.41 | 1993 | 11.734 | 1992 | 12.134 | 1991 | 12.498 | 1990 | 12.806 | 1989 | 13.265 | 1988 | 13.562 | 1987 | 14.016 | 1986 | 14.32 | 1985 | 14.736 | 1984 | 15.137 | 1983 | 15.607 | 1982 | 15.865 | 1981 | 16.28 | 1980 | 16.642 | 1979 | 16.988 | 1978 | 17.325 | 1977 | 17.699 | 1976 | 18.013 | 1975 | 19.267 | 1974 | 18.655 | 1973 | 19.036 | 1972 | 19.419 | 1971 | 19.922 | 1970 | 20.45 | 1969 | 21.003 | 1968 | 21.581 | 1967 | 22.208 | 1966 | 22.743 | 1965 | 23.169 | 1964 | 23.607 | 1963 | 23.942 | 1962 | 24.278 | 1961 | 24.68 | 1960 | 25.08 |
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