Year | Value | 2021 | 7.556 | 2020 | 7.425 | 2019 | 7.29 | 2018 | 7.187 | 2017 | 7.097 | 2016 | 7.021 | 2015 | 6.975 | 2014 | 6.94 | 2013 | 6.906 | 2012 | 6.859 | 2011 | 6.848 | 2010 | 6.876 | 2009 | 6.86 | 2008 | 6.831 | 2007 | 6.744 | 2006 | 6.643 | 2005 | 6.544 | 2004 | 6.433 | 2003 | 6.348 | 2002 | 6.3 | 2001 | 6.28 | 2000 | 6.388 | 1999 | 6.276 | 1998 | 6.356 | 1997 | 6.44 | 1996 | 6.544 | 1995 | 6.678 | 1994 | 6.806 | 1993 | 6.89 | 1992 | 6.99 | 1991 | 7.111 | 1990 | 7.248 | 1989 | 7.351 | 1988 | 7.502 | 1987 | 7.659 | 1986 | 7.789 | 1985 | 7.947 | 1984 | 8.151 | 1983 | 8.389 | 1982 | 8.637 | 1981 | 8.864 | 1980 | 9.085 | 1979 | 9.334 | 1978 | 9.57 | 1977 | 9.797 | 1976 | 10.037 | 1975 | 10.301 | 1974 | 10.566 | 1973 | 10.516 | 1972 | 10.533 | 1971 | 10.599 | 1970 | 11.141 | 1969 | 12.042 | 1968 | 12.995 | 1967 | 13.645 | 1966 | 13.801 | 1965 | 14.013 | 1964 | 14.291 | 1963 | 14.635 | 1962 | 15.089 | 1961 | 15.623 | 1960 | 16.121 |
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