Year | Value | 2021 | 80.7 | 2020 | 79.9 | 2019 | 80.2 | 2018 | 80.1 | 2017 | 79.9 | 2016 | 80.1 | 2015 | 80 | 2014 | 79.4 | 2013 | 79.8 | 2012 | 79.1 | 2011 | 78.5 | 2010 | 77.9 | 2009 | 78.1 | 2008 | 78.1 | 2007 | 76.7 | 2006 | 76.8 | 2005 | 76.7 | 2004 | 76 | 2003 | 74.8 | 2002 | 74.6 | 2001 | 74.8 | 2000 | 74.8 | 1999 | 74.6 | 1998 | 73.7 | 1997 | 74.1 | 1996 | 73.3 | 1995 | 73 | 1994 | 73.2 | 1993 | 72.2 | 1992 | 72.6 | 1991 | 72 | 1990 | 72.411 | 1989 | 71.397 | 1988 | 71.097 | 1987 | 70.88 | 1986 | 70.356 | 1985 | 70.082 | 1984 | 69.622 | 1983 | 69.306 | 1982 | 69.084 | 1981 | 68.94 | 1980 | 69.159 | 1979 | 68.702 | 1978 | 67.868 | 1977 | 67.745 | 1976 | 66.421 | 1975 | 66.923 | 1974 | 66.644 | 1973 | 66.315 | 1972 | 66.885 | 1971 | 65.685 | 1970 | 66.102 | 1969 | 66.089 | 1968 | 66.7 | 1967 | 65.855 | 1966 | 65.901 | 1965 | 65.682 | 1964 | 65.879 | 1963 | 65.839 | 1962 | 64.872 | 1961 | 66.46 | 1960 | 65.814 |
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