Year | Value | 2021 | 7.18 | 2020 | 7.07 | 2019 | 7.09 | 2018 | 7.08 | 2017 | 7.06 | 2016 | 7.04 | 2015 | 7.07 | 2014 | 7.12 | 2013 | 7.13 | 2012 | 7.13 | 2011 | 7.14 | 2010 | 7.11 | 2009 | 7.08 | 2008 | 7.06 | 2007 | 6.93 | 2006 | 6.81 | 2005 | 6.51 | 2004 | 6.42 | 2003 | 6.4 | 2002 | 6.41 | 2001 | 6.43 | 2000 | 6.45 | 1999 | 6.46 | 1998 | 6.5 | 1997 | 6.51 | 1996 | 6.56 | 1995 | 6.57 | 1994 | 6.49 | 1993 | 6.64 | 1992 | 6.64 | 1991 | 6.7 | 1990 | 6.67 | 1989 | 6.54 | 1988 | 6.64 | 1987 | 6.72 | 1986 | 6.86 | 1985 | 6.78 | 1984 | 6.82 | 1983 | 6.9 | 1982 | 6.6 | 1981 | 6.36 | 1980 | 6.34 | 1979 | 6.21 | 1978 | 6.25 | 1977 | 6.87 | 1976 | 7.25 | 1975 | 7.32 | 1974 | 7.34 | 1973 | 7.04 | 1972 | 7.61 | 1971 | 7.32 | 1970 | 7.6 | 1969 | 8.03 | 1968 | 8.21 | 1967 | 8.43 | 1966 | 8.83 | 1965 | 9.5 | 1964 | 11.5 | 1963 | 10.04 | 1962 | 10.02 | 1961 | 14.24 | 1960 | 25.43 |
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