Year | Value | 2021 | 81.3 | 2020 | 81.2 | 2019 | 80.9 | 2018 | 80.7 | 2017 | 80.5 | 2016 | 80.4 | 2015 | 80.4 | 2014 | 80.3 | 2013 | 80.1 | 2012 | 79.9 | 2011 | 79.7 | 2010 | 79.5 | 2009 | 79.3 | 2008 | 79.2 | 2007 | 79 | 2006 | 78.7 | 2005 | 78.5 | 2004 | 78.1 | 2003 | 77.8 | 2002 | 77.4 | 2001 | 77 | 2000 | 76.6 | 1999 | 76.2 | 1998 | 75.9 | 1997 | 75.7 | 1996 | 75.2 | 1995 | 75 | 1994 | 75 | 1993 | 75 | 1992 | 74.5 | 1991 | 74.3 | 1990 | 73.98 | 1989 | 73.66 | 1988 | 73.34 | 1987 | 73.02 | 1986 | 72.7 | 1985 | 72.4 | 1984 | 72.1 | 1983 | 71.8 | 1982 | 71.5 | 1981 | 71.2 | 1980 | 70.88 | 1979 | 70.56 | 1978 | 70.24 | 1977 | 69.92 | 1976 | 69.6 | 1975 | 69.24 | 1974 | 68.88 | 1973 | 68.52 | 1972 | 68.16 | 1971 | 67.8 | 1970 | 67.76 | 1969 | 67.72 | 1968 | 67.68 | 1967 | 67.64 | 1966 | 67.6 | 1965 | 67.66 | 1964 | 67.72 | 1963 | 67.78 | 1962 | 67.84 | 1961 | 67.9 | 1960 | 67.785714285714 |
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