Year | Value | 2021 | 7.922 | 2020 | 7.264 | 2019 | 7.14 | 2018 | 7.027 | 2017 | 6.897 | 2016 | 6.814 | 2015 | 6.724 | 2014 | 6.627 | 2013 | 6.547 | 2012 | 6.464 | 2011 | 6.393 | 2010 | 6.307 | 2009 | 6.236 | 2008 | 6.189 | 2007 | 6.122 | 2006 | 6.033 | 2005 | 6.323 | 2004 | 6.419 | 2003 | 6.23 | 2002 | 6.138 | 2001 | 6.088 | 2000 | 6.043 | 1999 | 5.822 | 1998 | 5.588 | 1997 | 5.614 | 1996 | 5.818 | 1995 | 5.964 | 1994 | 5.747 | 1993 | 5.695 | 1992 | 5.654 | 1991 | 5.612 | 1990 | 5.602 | 1989 | 5.615 | 1988 | 5.663 | 1987 | 5.665 | 1986 | 5.935 | 1985 | 6.153 | 1984 | 6.395 | 1983 | 6.69 | 1982 | 6.89 | 1981 | 7.08 | 1980 | 7.27 | 1979 | 7.535 | 1978 | 7.702 | 1977 | 7.863 | 1976 | 8.045 | 1975 | 8.378 | 1974 | 8.73 | 1973 | 9.108 | 1972 | 9.531 | 1971 | 9.859 | 1970 | 10.33 | 1969 | 10.802 | 1968 | 11.26 | 1967 | 11.597 | 1966 | 11.958 | 1965 | 12.342 | 1964 | 12.817 | 1963 | 13.297 | 1962 | 13.625 | 1961 | 13.929 | 1960 | 14.737 |
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