Year | Value | 2021 | 13.326 | 2020 | 13.301 | 2019 | 13.272 | 2018 | 13.191 | 2017 | 13.13 | 2016 | 13.167 | 2015 | 13.447 | 2014 | 13.092 | 2013 | 13.369 | 2012 | 13.516 | 2011 | 13.679 | 2010 | 14.009 | 2009 | 14.378 | 2008 | 14.902 | 2007 | 15.45 | 2006 | 15.947 | 2005 | 15.615 | 2004 | 15.813 | 2003 | 16.128 | 2002 | 16.867 | 2001 | 18.854 | 2000 | 17.709 | 1999 | 19.46 | 1998 | 18.012 | 1997 | 18.688 | 1996 | 19.881 | 1995 | 21.287 | 1994 | 23.008 | 1993 | 24.833 | 1992 | 26.137 | 1991 | 24.603 | 1990 | 24.243 | 1989 | 24.507 | 1988 | 25.153 | 1987 | 23.37 | 1986 | 24.398 | 1985 | 23.852 | 1984 | 23.287 | 1983 | 24.584 | 1982 | 22.524 | 1981 | 21.741 | 1980 | 21.401 | 1979 | 21.357 | 1978 | 21.586 | 1977 | 22.085 | 1976 | 22.803 | 1975 | 23.899 | 1974 | 25.219 | 1973 | 26.499 | 1972 | 27.988 | 1971 | 29.377 | 1970 | 30.852 | 1969 | 32.944 | 1968 | 30.284 | 1967 | 31.648 | 1966 | 36.299 | 1965 | 30.664 | 1964 | 31.374 | 1963 | 34.18 | 1962 | 34.222 | 1961 | 35.09 | 1960 | 45.714 |
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