Year | Value | 2021 | 11.393 | 2020 | 11.041 | 2019 | 10.873 | 2018 | 11.23 | 2017 | 11.544 | 2016 | 11.711 | 2015 | 12.15 | 2014 | 13.517 | 2013 | 13.392 | 2012 | 13.622 | 2011 | 14.092 | 2010 | 14.534 | 2009 | 14.907 | 2008 | 15.313 | 2007 | 15.696 | 2006 | 16.08 | 2005 | 16.367 | 2004 | 16.658 | 2003 | 16.889 | 2002 | 17.168 | 2001 | 17.245 | 2000 | 17.325 | 1999 | 17.159 | 1998 | 17.068 | 1997 | 16.99 | 1996 | 16.795 | 1995 | 16.577 | 1994 | 16.4 | 1993 | 16.273 | 1992 | 16.206 | 1991 | 16.132 | 1990 | 16.088 | 1989 | 16.071 | 1988 | 16.07 | 1987 | 16.09 | 1986 | 16.126 | 1985 | 16.19 | 1984 | 16.273 | 1983 | 16.349 | 1982 | 16.448 | 1981 | 16.535 | 1980 | 16.68 | 1979 | 16.825 | 1978 | 17.003 | 1977 | 17.212 | 1976 | 17.461 | 1975 | 17.833 | 1974 | 18.271 | 1973 | 18.743 | 1972 | 19.238 | 1971 | 19.767 | 1970 | 20.302 | 1969 | 20.852 | 1968 | 21.39 | 1967 | 21.893 | 1966 | 22.4 | 1965 | 22.893 | 1964 | 23.394 | 1963 | 23.898 | 1962 | 24.396 | 1961 | 24.9 | 1960 | 25.41 |
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