Year | Value | 2021 | 80.6 | 2020 | 80 | 2019 | 81.4 | 2018 | 81.2 | 2017 | 80.8 | 2016 | 81 | 2015 | 80.3 | 2014 | 80.7 | 2013 | 80.3 | 2012 | 79.8 | 2011 | 79.7 | 2010 | 79.5 | 2009 | 79.1 | 2008 | 78.9 | 2007 | 78.8 | 2006 | 78.6 | 2005 | 78.1 | 2004 | 78 | 2003 | 77.3 | 2002 | 77.4 | 2001 | 77.2 | 2000 | 76.9 | 1999 | 76.4 | 1998 | 76 | 1997 | 75.8 | 1996 | 75.4 | 1995 | 75 | 1994 | 74.8 | 1993 | 74.6 | 1992 | 74.2 | 1991 | 73.8 | 1990 | 73.8 | 1989 | 73.6 | 1988 | 73.2 | 1987 | 73 | 1986 | 72.6 | 1985 | 72.3 | 1984 | 72.17 | 1983 | 71.45 | 1982 | 71.6 | 1981 | 71.11 | 1980 | 70.67 | 1979 | 70.71 | 1978 | 70.42 | 1977 | 70.15 | 1976 | 69.87 | 1975 | 69.54 | 1974 | 69.71 | 1973 | 69.08 | 1972 | 69.09 | 1971 | 68.88 | 1970 | 68.71 | 1969 | 67.89 | 1968 | 67.98 | 1967 | 68.22 | 1966 | 68.17 | 1965 | 67.44 | 1964 | 67.58 | 1963 | 66.57 | 1962 | 66.54 | 1961 | 67.17 | 1960 | 66.68 |
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