Year | Value | 2021 | 6.17 | 2020 | 6.073 | 2019 | 5.658 | 2018 | 5.637 | 2017 | 5.642 | 2016 | 5.674 | 2015 | 5.705 | 2014 | 5.741 | 2013 | 5.796 | 2012 | 5.86 | 2011 | 5.91 | 2010 | 5.966 | 2009 | 5.987 | 2008 | 6.018 | 2007 | 6.068 | 2006 | 6.13 | 2005 | 6.177 | 2004 | 6.259 | 2003 | 6.276 | 2002 | 6.318 | 2001 | 6.365 | 2000 | 6.432 | 1999 | 6.5 | 1998 | 6.59 | 1997 | 6.678 | 1996 | 6.769 | 1995 | 6.915 | 1994 | 7.027 | 1993 | 7.189 | 1992 | 7.37 | 1991 | 7.53 | 1990 | 7.706 | 1989 | 7.944 | 1988 | 8.241 | 1987 | 8.573 | 1986 | 8.944 | 1985 | 9.373 | 1984 | 9.846 | 1983 | 10.326 | 1982 | 10.833 | 1981 | 11.334 | 1980 | 11.814 | 1979 | 12.341 | 1978 | 12.898 | 1977 | 13.45 | 1976 | 13.99 | 1975 | 14.488 | 1974 | 14.906 | 1973 | 15.304 | 1972 | 15.661 | 1971 | 16.024 | 1970 | 16.387 | 1969 | 16.808 | 1968 | 17.308 | 1967 | 17.861 | 1966 | 18.441 | 1965 | 19.004 | 1964 | 19.57 | 1963 | 20.153 | 1962 | 20.732 | 1961 | 21.213 | 1960 | 22.745 |
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