Year | Value | 2022 | 22.661 | 2021 | 22.174 | 2020 | 21.695 | 2019 | 21.225 | 2018 | 20.763 | 2017 | 20.31 | 2016 | 19.866 | 2015 | 19.428 | 2014 | 18.998 | 2013 | 18.575 | 2012 | 18.16 | 2011 | 17.735 | 2010 | 17.319 | 2009 | 16.91 | 2008 | 16.51 | 2007 | 16.116 | 2006 | 15.899 | 2005 | 15.7 | 2004 | 15.504 | 2003 | 15.31 | 2002 | 15.118 | 2001 | 14.927 | 2000 | 14.74 | 1999 | 14.553 | 1998 | 14.369 | 1997 | 14.186 | 1996 | 14.006 | 1995 | 13.827 | 1994 | 13.627 | 1993 | 13.37 | 1992 | 13.116 | 1991 | 12.867 | 1990 | 12.621 | 1989 | 12.38 | 1988 | 12.143 | 1987 | 11.909 | 1986 | 11.679 | 1985 | 11.453 | 1984 | 11.232 | 1983 | 11.02 | 1982 | 10.813 | 1981 | 10.61 | 1980 | 10.41 | 1979 | 10.214 | 1978 | 10.02 | 1977 | 9.83 | 1976 | 9.644 | 1975 | 9.46 | 1974 | 9.279 | 1973 | 9.102 | 1972 | 8.928 | 1971 | 8.756 | 1970 | 8.588 | 1969 | 8.422 | 1968 | 8.26 | 1967 | 8.1 | 1966 | 7.84 | 1965 | 7.587 | 1964 | 7.342 | 1963 | 7.104 | 1962 | 6.874 | 1961 | 6.65 | 1960 | 6.433 |
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