Year | Value | 2022 | 24.576 | 2021 | 24.369 | 2020 | 24.171 | 2019 | 23.981 | 2018 | 23.799 | 2017 | 23.625 | 2016 | 23.459 | 2015 | 23.3 | 2014 | 23.149 | 2013 | 22.999 | 2012 | 22.849 | 2011 | 22.7 | 2010 | 22.48 | 2009 | 22.262 | 2008 | 22.045 | 2007 | 21.829 | 2006 | 21.91 | 2005 | 22.038 | 2004 | 22.166 | 2003 | 22.296 | 2002 | 22.425 | 2001 | 22.555 | 2000 | 22.686 | 1999 | 22.817 | 1998 | 22.949 | 1997 | 23.081 | 1996 | 22.722 | 1995 | 22.286 | 1994 | 21.857 | 1993 | 21.434 | 1992 | 21.018 | 1991 | 20.607 | 1990 | 20.202 | 1989 | 19.803 | 1988 | 19.41 | 1987 | 19.022 | 1986 | 18.641 | 1985 | 18.266 | 1984 | 17.897 | 1983 | 17.533 | 1982 | 17.176 | 1981 | 16.824 | 1980 | 16.478 | 1979 | 16.137 | 1978 | 15.803 | 1977 | 15.474 | 1976 | 15.037 | 1975 | 14.004 | 1974 | 13.033 | 1973 | 12.12 | 1972 | 11.264 | 1971 | 10.458 | 1970 | 9.705 | 1969 | 9.001 | 1968 | 8.344 | 1967 | 7.729 | 1966 | 7.157 | 1965 | 6.494 | 1964 | 5.876 | 1963 | 5.312 | 1962 | 4.8 | 1961 | 4.335 | 1960 | 3.913 |
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