Year | Value | 2021 | 69.4 | 2020 | 70.4 | 2019 | 71.9 | 2018 | 71.7 | 2017 | 71.7 | 2016 | 71.6 | 2015 | 71.4 | 2014 | 71.3 | 2013 | 71.6 | 2012 | 70.9 | 2011 | 70.8 | 2010 | 69.8 | 2009 | 69.7 | 2008 | 69.2 | 2007 | 69.2 | 2006 | 68.7 | 2005 | 68.4 | 2004 | 68 | 2003 | 67.7 | 2002 | 67.4 | 2001 | 67.6 | 2000 | 67.7 | 1999 | 67 | 1998 | 66.1 | 1997 | 65.2 | 1996 | 65.3 | 1995 | 65.7 | 1994 | 65.9 | 1993 | 66.1 | 1992 | 66.56 | 1991 | 66.56 | 1990 | 66.59 | 1989 | 66.56 | 1988 | 66.51 | 1987 | 66.3 | 1986 | 66.55 | 1985 | 66.78 | 1984 | 66.81 | 1983 | 66.98 | 1982 | 66.8 | 1981 | 66.7 | 1980 | 66.53 | 1979 | 66.68 | 1978 | 67.1 | 1977 | 67.42 | 1976 | 67.45 | 1975 | 67.37 | 1974 | 67.29 | 1973 | 66.83 | 1972 | 66.28 | 1971 | 66.27 | 1970 | 65.219 | 1969 | 64.495 | 1968 | 65.515 | 1967 | 65.514 | 1966 | 67.004 | 1965 | 65.978 | 1964 | 66.09 | 1963 | 65.4 | 1962 | 63.602 | 1961 | 64.303 | 1960 | 64.242 |
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