Year | Value | 2021 | 14.652 | 2020 | 10.23 | 2019 | 9.861 | 2018 | 9.815 | 2017 | 9.622 | 2016 | 9.348 | 2015 | 9.063 | 2014 | 8.833 | 2013 | 8.672 | 2012 | 8.571 | 2011 | 8.421 | 2010 | 8.297 | 2009 | 8.191 | 2008 | 8.096 | 2007 | 8.001 | 2006 | 7.907 | 2005 | 7.806 | 2004 | 7.695 | 2003 | 7.567 | 2002 | 7.436 | 2001 | 7.318 | 2000 | 7.244 | 1999 | 7.22 | 1998 | 7.238 | 1997 | 7.281 | 1996 | 7.314 | 1995 | 7.32 | 1994 | 7.264 | 1993 | 7.195 | 1992 | 7.085 | 1991 | 6.962 | 1990 | 6.841 | 1989 | 6.732 | 1988 | 6.638 | 1987 | 6.557 | 1986 | 6.484 | 1985 | 6.43 | 1984 | 6.393 | 1983 | 6.379 | 1982 | 6.392 | 1981 | 6.437 | 1980 | 6.262 | 1979 | 6.136 | 1978 | 6.02 | 1977 | 5.974 | 1976 | 5.983 | 1975 | 6.054 | 1974 | 6.183 | 1973 | 6.349 | 1972 | 6.533 | 1971 | 6.703 | 1970 | 6.936 | 1969 | 7.146 | 1968 | 7.335 | 1967 | 7.513 | 1966 | 7.693 | 1965 | 7.877 | 1964 | 8.068 | 1963 | 8.482 | 1962 | 8.381 | 1961 | 8.545 | 1960 | 8.629 |
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