Year | Value | 2021 | 7.104 | 2020 | 6.801 | 2019 | 6.518 | 2018 | 6.736 | 2017 | 6.79 | 2016 | 6.81 | 2015 | 7.049 | 2014 | 7.076 | 2013 | 7.201 | 2012 | 7.38 | 2011 | 7.427 | 2010 | 7.713 | 2009 | 7.801 | 2008 | 8.066 | 2007 | 8.257 | 2006 | 8.476 | 2005 | 8.831 | 2004 | 9.062 | 2003 | 9.407 | 2002 | 9.748 | 2001 | 9.986 | 2000 | 10.385 | 1999 | 10.769 | 1998 | 11.108 | 1997 | 11.569 | 1996 | 12.02 | 1995 | 12.395 | 1994 | 12.738 | 1993 | 13.077 | 1992 | 13.597 | 1991 | 14.036 | 1990 | 14.463 | 1989 | 14.853 | 1988 | 15.213 | 1987 | 15.494 | 1986 | 15.791 | 1985 | 15.969 | 1984 | 16.086 | 1983 | 16.136 | 1982 | 16.159 | 1981 | 16.161 | 1980 | 16.176 | 1979 | 16.216 | 1978 | 16.276 | 1977 | 16.332 | 1976 | 16.403 | 1975 | 16.499 | 1974 | 16.741 | 1973 | 17.045 | 1972 | 17.419 | 1971 | 17.733 | 1970 | 17.965 | 1969 | 18.289 | 1968 | 18.649 | 1967 | 19.019 | 1966 | 19.368 | 1965 | 19.651 | 1964 | 19.973 | 1963 | 20.356 | 1962 | 20.73 | 1961 | 21.139 | 1960 | 21.524 |
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