Year | Value | 2021 | 5.9 | 2020 | 6 | 2019 | 6.4 | 2018 | 6.7 | 2017 | 7.3 | 2016 | 8.3 | 2015 | 9 | 2014 | 9.7 | 2013 | 10.1 | 2012 | 10.6 | 2011 | 11.1 | 2010 | 11.3 | 2009 | 11.72 | 2008 | 11.79 | 2007 | 11.86 | 2006 | 12.41 | 2005 | 12.96 | 2004 | 13.16 | 2003 | 13.1 | 2002 | 13.7 | 2001 | 14.59 | 2000 | 15.59 | 1999 | 15.6 | 1998 | 15.7 | 1997 | 16.2 | 1996 | 16.9 | 1995 | 17 | 1994 | 17.5 | 1993 | 17.9 | 1992 | 17.8 | 1991 | 18.1 | 1990 | 18.5 | 1989 | 19.1 | 1988 | 19.3 | 1987 | 19.5 | 1986 | 19.45 | 1985 | 19.4 | 1984 | 19.3 | 1983 | 20.1 | 1982 | 21.05 | 1981 | 22 | 1980 | 22.8 | 1979 | 23.4 | 1978 | 24.1 | 1977 | 24.5 | 1976 | 24.2 | 1975 | 23.8 | 1974 | 24.3 | 1973 | 23.3 | 1972 | 24 | 1971 | 25.6 | 1970 | 24.8 | 1969 | 24.9 | 1968 | 25.5 | 1967 | 26.7 | 1966 | 28.9 | 1965 | 30.7 | 1964 | 31 | 1963 | 31 | 1962 | 31.3 | 1961 | 31.4 | 1960 | 32.4 |
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