Year | Value | 2022 | 13.582 | 2021 | 13.456 | 2020 | 13.345 | 2019 | 13.25 | 2018 | 13.169 | 2017 | 13.102 | 2016 | 13.05 | 2015 | 13.012 | 2014 | 12.988 | 2013 | 12.978 | 2012 | 12.982 | 2011 | 13 | 2010 | 13.019 | 2009 | 13.037 | 2008 | 13.055 | 2007 | 13.073 | 2006 | 13.091 | 2005 | 13.109 | 2004 | 13.127 | 2003 | 13.146 | 2002 | 13.164 | 2001 | 13.182 | 2000 | 13.204 | 1999 | 13.375 | 1998 | 13.549 | 1997 | 13.724 | 1996 | 13.901 | 1995 | 14.081 | 1994 | 14.262 | 1993 | 14.445 | 1992 | 14.629 | 1991 | 14.816 | 1990 | 14.994 | 1989 | 14.791 | 1988 | 14.589 | 1987 | 14.39 | 1986 | 14.193 | 1985 | 13.998 | 1984 | 13.806 | 1983 | 13.616 | 1982 | 13.428 | 1981 | 13.242 | 1980 | 13.047 | 1979 | 12.817 | 1978 | 12.59 | 1977 | 12.366 | 1976 | 12.147 | 1975 | 11.93 | 1974 | 11.717 | 1973 | 11.507 | 1972 | 11.3 | 1971 | 11.078 | 1970 | 9.796 | 1969 | 8.649 | 1968 | 7.625 | 1967 | 6.712 | 1966 | 5.902 | 1965 | 5.47 | 1964 | 5.069 | 1963 | 4.694 | 1962 | 4.347 | 1961 | 4.024 | 1960 | 3.725 |
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