Year | Value | 2022 | 13.512 | 2021 | 13.638 | 2020 | 13.759 | 2019 | 13.876 | 2018 | 13.988 | 2017 | 14.096 | 2016 | 14.2 | 2015 | 14.299 | 2014 | 14.398 | 2013 | 14.498 | 2012 | 14.598 | 2011 | 14.7 | 2010 | 14.818 | 2009 | 14.937 | 2008 | 15.057 | 2007 | 15.178 | 2006 | 15.3 | 2005 | 15.418 | 2004 | 15.537 | 2003 | 15.657 | 2002 | 15.778 | 2001 | 15.9 | 2000 | 15.765 | 1999 | 15.63 | 1998 | 15.497 | 1997 | 15.364 | 1996 | 15.233 | 1995 | 15.102 | 1994 | 14.972 | 1993 | 14.843 | 1992 | 14.715 | 1991 | 14.597 | 1990 | 14.567 | 1989 | 14.537 | 1988 | 14.507 | 1987 | 14.478 | 1986 | 14.448 | 1985 | 14.418 | 1984 | 14.389 | 1983 | 14.359 | 1982 | 14.33 | 1981 | 14.3 | 1980 | 14.448 | 1979 | 14.597 | 1978 | 14.748 | 1977 | 14.9 | 1976 | 15.053 | 1975 | 15.208 | 1974 | 15.364 | 1973 | 15.522 | 1972 | 15.68 | 1971 | 15.84 | 1970 | 16.001 | 1969 | 16.164 | 1968 | 16.328 | 1967 | 16.493 | 1966 | 16.66 | 1965 | 16.932 | 1964 | 17.208 | 1963 | 17.489 | 1962 | 17.772 | 1961 | 18.059 | 1960 | 18.471 |
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