Year | Value | 2022 | 6.008 | 2021 | 6.056 | 2020 | 6.102 | 2019 | 6.145 | 2018 | 6.187 | 2017 | 6.227 | 2016 | 6.265 | 2015 | 6.3 | 2014 | 6.333 | 2013 | 6.367 | 2012 | 6.4 | 2011 | 6.413 | 2010 | 6.426 | 2009 | 6.489 | 2008 | 6.605 | 2007 | 6.722 | 2006 | 6.841 | 2005 | 6.963 | 2004 | 7.086 | 2003 | 7.211 | 2002 | 7.338 | 2001 | 7.468 | 2000 | 7.599 | 1999 | 7.733 | 1998 | 7.879 | 1997 | 8.04 | 1996 | 8.203 | 1995 | 8.37 | 1994 | 8.54 | 1993 | 8.713 | 1992 | 8.888 | 1991 | 9.068 | 1990 | 9.25 | 1989 | 9.476 | 1988 | 9.706 | 1987 | 9.943 | 1986 | 10.184 | 1985 | 10.43 | 1984 | 10.681 | 1983 | 10.938 | 1982 | 11.2 | 1981 | 11.467 | 1980 | 11.74 | 1979 | 12.045 | 1978 | 12.356 | 1977 | 12.674 | 1976 | 12.998 | 1975 | 13.331 | 1974 | 13.67 | 1973 | 14.017 | 1972 | 14.37 | 1971 | 14.731 | 1970 | 15.1 | 1969 | 15.517 | 1968 | 15.943 | 1967 | 16.379 | 1966 | 16.825 | 1965 | 17.28 | 1964 | 17.744 | 1963 | 18.219 | 1962 | 18.703 | 1961 | 19.197 | 1960 | 19.7 |
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