Year | Value | 2021 | 9.131 | 2020 | 7.9 | 2019 | 7.701 | 2018 | 7.783 | 2017 | 7.386 | 2016 | 7.134 | 2015 | 6.797 | 2014 | 6.739 | 2013 | 6.662 | 2012 | 6.596 | 2011 | 6.618 | 2010 | 6.708 | 2009 | 6.316 | 2008 | 6.983 | 2007 | 6.717 | 2006 | 6.744 | 2005 | 6.543 | 2004 | 6.493 | 2003 | 7.048 | 2002 | 6.505 | 2001 | 6.809 | 2000 | 6.98 | 1999 | 7.287 | 1998 | 6.757 | 1997 | 6.906 | 1996 | 6.659 | 1995 | 6.503 | 1994 | 6.766 | 1993 | 6.559 | 1992 | 6.724 | 1991 | 6.443 | 1990 | 6.694 | 1989 | 6.59 | 1988 | 6.595 | 1987 | 6.651 | 1986 | 6.657 | 1985 | 7.004 | 1984 | 6.969 | 1983 | 6.805 | 1982 | 6.921 | 1981 | 6.895 | 1980 | 6.879 | 1979 | 6.726 | 1978 | 6.809 | 1977 | 7.111 | 1976 | 7.23 | 1975 | 6.943 | 1974 | 6.888 | 1973 | 7.486 | 1972 | 7.798 | 1971 | 7.588 | 1970 | 7.687 | 1969 | 7.725 | 1968 | 7.642 | 1967 | 7.476 | 1966 | 7.613 | 1965 | 7.68 | 1964 | 7.785 | 1963 | 7.758 | 1962 | 7.907 | 1961 | 8.105 | 1960 | 8.037 |
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