Year | Value | 2021 | 79.3 | 2020 | 79.2 | 2019 | 79.9 | 2018 | 79.7 | 2017 | 79.6 | 2016 | 79.5 | 2015 | 79.2 | 2014 | 79.5 | 2013 | 79 | 2012 | 78.7 | 2011 | 78.7 | 2010 | 78.2 | 2009 | 78 | 2008 | 77.8 | 2007 | 77.6 | 2006 | 77.3 | 2005 | 76.7 | 2004 | 76.7 | 2003 | 75.7 | 2002 | 75.7 | 2001 | 75.5 | 2000 | 75.3 | 1999 | 75 | 1998 | 74.8 | 1997 | 74.5 | 1996 | 74.1 | 1995 | 73.8 | 1994 | 73.6 | 1993 | 73.3 | 1992 | 73.1 | 1991 | 72.8 | 1990 | 72.6 | 1989 | 72.3 | 1988 | 72.1 | 1987 | 71.8 | 1986 | 71.6 | 1985 | 71.3 | 1984 | 71 | 1983 | 70.8 | 1982 | 70.5 | 1981 | 70.3 | 1980 | 70.1 | 1979 | 69.9 | 1978 | 69.7 | 1977 | 69.4 | 1976 | 69.2 | 1975 | 69 | 1974 | 68.8 | 1973 | 68.6 | 1972 | 68.4 | 1971 | 68.2 | 1970 | 68 | 1969 | 67.8 | 1968 | 67.7 | 1967 | 67.6 | 1966 | 67.4 | 1965 | 67.3 | 1964 | 67.2 | 1963 | 67.1 | 1962 | 66.9 | 1961 | 66.8 | 1960 | 66.6 |
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