Year | Value | 2021 | 9.448 | 2020 | 7.35 | 2019 | 6.71 | 2018 | 6.644 | 2017 | 6.593 | 2016 | 6.603 | 2015 | 6.67 | 2014 | 6.79 | 2013 | 6.96 | 2012 | 7.118 | 2011 | 7.267 | 2010 | 7.385 | 2009 | 7.479 | 2008 | 7.558 | 2007 | 7.642 | 2006 | 7.743 | 2005 | 7.876 | 2004 | 8.04 | 2003 | 8.188 | 2002 | 8.363 | 2001 | 8.558 | 2000 | 8.701 | 1999 | 8.875 | 1998 | 9.05 | 1997 | 9.229 | 1996 | 9.419 | 1995 | 9.612 | 1994 | 9.807 | 1993 | 10.021 | 1992 | 10.23 | 1991 | 10.455 | 1990 | 10.691 | 1989 | 10.956 | 1988 | 11.236 | 1987 | 11.522 | 1986 | 11.82 | 1985 | 12.102 | 1984 | 12.412 | 1983 | 12.72 | 1982 | 13.044 | 1981 | 13.37 | 1980 | 13.676 | 1979 | 13.965 | 1978 | 14.288 | 1977 | 14.662 | 1976 | 15.009 | 1975 | 15.381 | 1974 | 15.786 | 1973 | 16.27 | 1972 | 16.643 | 1971 | 16.938 | 1970 | 17.228 | 1969 | 17.51 | 1968 | 17.778 | 1967 | 19.082 | 1966 | 19.342 | 1965 | 19.642 | 1964 | 18.761 | 1963 | 18.964 | 1962 | 19.205 | 1961 | 19.446 | 1960 | 19.633 |
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