Year | Value | 2021 | 80.6 | 2020 | 81.3 | 2019 | 82.2 | 2018 | 82 | 2017 | 82 | 2016 | 82.1 | 2015 | 81.6 | 2014 | 82 | 2013 | 81.3 | 2012 | 81.2 | 2011 | 81.1 | 2010 | 80.6 | 2009 | 80.1 | 2008 | 80.1 | 2007 | 79.9 | 2006 | 79.7 | 2005 | 79.1 | 2004 | 79 | 2003 | 78.5 | 2002 | 78.5 | 2001 | 78.4 | 2000 | 78.4 | 1999 | 78.1 | 1998 | 78.1 | 1997 | 77.4 | 1996 | 77.3 | 1995 | 76.65 | 1994 | 76.64 | 1993 | 76.43 | 1992 | 76.19 | 1991 | 75.75 | 1990 | 75.42 | 1989 | 75.43 | 1988 | 75.36 | 1987 | 75.2 | 1986 | 74.68 | 1985 | 74.77 | 1984 | 74.51 | 1983 | 74.31 | 1982 | 74.47 | 1981 | 74.41 | 1980 | 73.93 | 1979 | 74.34 | 1978 | 74.26 | 1977 | 74.21 | 1976 | 74.2 | 1975 | 74 | 1974 | 73.59 | 1973 | 73.69 | 1972 | 73.68 | 1971 | 73.37 | 1970 | 73 | 1969 | 73.06 | 1968 | 73.38 | 1967 | 73.66 | 1966 | 73.75 | 1965 | 73.39 | 1964 | 73.63 | 1963 | 73.48 | 1962 | 72.86 | 1961 | 73.55 | 1960 | 73.34 |
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