Year | Value | 2021 | 81.7 | 2020 | 81.6 | 2019 | 81.3 | 2018 | 81.1 | 2017 | 81 | 2016 | 80.7 | 2015 | 80.5 | 2014 | 80.1 | 2013 | 79.8 | 2012 | 79.5 | 2011 | 79.1 | 2010 | 78.9 | 2009 | 78.6 | 2008 | 78.3 | 2007 | 78.2 | 2006 | 78.1 | 2005 | 77.7 | 2004 | 77.5 | 2003 | 77 | 2002 | 76.5 | 2001 | 76.2 | 2000 | 76 | 1999 | 75.6 | 1998 | 75.5 | 1997 | 75.45 | 1996 | 75.37 | 1995 | 74.8 | 1994 | 74.88 | 1993 | 74.22 | 1992 | 74.16 | 1991 | 74.01 | 1990 | 73.43 | 1989 | 73.32 | 1988 | 73.04 | 1987 | 72.75 | 1986 | 72.89 | 1985 | 72.59 | 1984 | 73 | 1983 | 72.74 | 1982 | 72.65 | 1981 | 72.63 | 1980 | 72.34 | 1979 | 72.17 | 1978 | 72.36 | 1977 | 72.26 | 1976 | 72.02 | 1975 | 71.72 | 1974 | 71.7 | 1973 | 71.33 | 1972 | 71.33 | 1971 | 71.15 | 1970 | 71.01 | 1969 | 70.8 | 1968 | 71.22 | 1967 | 71.33 | 1966 | 71.41 | 1965 | 71.05 | 1964 | 71.23 | 1963 | 70.78 | 1962 | 70.97 | 1961 | 71.17 | 1960 | 71.34 |
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