Year | Value | 2021 | 7.258 | 2020 | 6.909 | 2019 | 6.856 | 2018 | 6.986 | 2017 | 7.054 | 2016 | 7.238 | 2015 | 7.418 | 2014 | 7.659 | 2013 | 7.786 | 2012 | 7.914 | 2011 | 8.184 | 2010 | 8.284 | 2009 | 8.559 | 2008 | 8.686 | 2007 | 8.924 | 2006 | 9.074 | 2005 | 9.299 | 2004 | 9.405 | 2003 | 9.538 | 2002 | 9.767 | 2001 | 9.847 | 2000 | 10.002 | 1999 | 10.167 | 1998 | 10.275 | 1997 | 10.421 | 1996 | 10.545 | 1995 | 10.62 | 1994 | 10.754 | 1993 | 10.875 | 1992 | 11.076 | 1991 | 11.266 | 1990 | 11.437 | 1989 | 11.593 | 1988 | 11.846 | 1987 | 12.021 | 1986 | 12.264 | 1985 | 12.549 | 1984 | 12.883 | 1983 | 13.151 | 1982 | 13.518 | 1981 | 13.754 | 1980 | 14.027 | 1979 | 14.309 | 1978 | 14.599 | 1977 | 14.984 | 1976 | 15.309 | 1975 | 15.698 | 1974 | 16.005 | 1973 | 16.347 | 1972 | 16.631 | 1971 | 16.963 | 1970 | 17.288 | 1969 | 17.674 | 1968 | 17.977 | 1967 | 18.302 | 1966 | 18.612 | 1965 | 18.945 | 1964 | 19.348 | 1963 | 19.671 | 1962 | 20.014 | 1961 | 20.315 | 1960 | 20.64 |
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