Year | Value | 2021 | 80.3 | 2020 | 79.6 | 2019 | 81.1 | 2018 | 80.7 | 2017 | 80.6 | 2016 | 80.5 | 2015 | 80.1 | 2014 | 80.4 | 2013 | 80.2 | 2012 | 79.5 | 2011 | 79.5 | 2010 | 78.7 | 2009 | 78.5 | 2008 | 78.2 | 2007 | 77.8 | 2006 | 77.7 | 2005 | 77 | 2004 | 76.7 | 2003 | 76.4 | 2002 | 76.3 | 2001 | 76.1 | 2000 | 75.6 | 1999 | 75.4 | 1998 | 75.3 | 1997 | 75.17 | 1996 | 74.54 | 1995 | 74.41 | 1994 | 74.36 | 1993 | 74.01 | 1992 | 73.81 | 1991 | 73.42 | 1990 | 73.34 | 1989 | 73.36 | 1988 | 73.43 | 1987 | 73.45 | 1986 | 73.33 | 1985 | 73.04 | 1984 | 73.11 | 1983 | 72.87 | 1982 | 73.1 | 1981 | 72.47 | 1980 | 72.32 | 1979 | 71.77 | 1978 | 71.32 | 1977 | 71.21 | 1976 | 70.75 | 1975 | 70.47 | 1974 | 70.16 | 1973 | 69.84 | 1972 | 70.14 | 1971 | 68.84 | 1970 | 69.32 | 1969 | 68.36 | 1968 | 68.85 | 1967 | 68.57 | 1966 | 68.46 | 1965 | 68.18 | 1964 | 67.79 | 1963 | 67.13 | 1962 | 67.08 | 1961 | 67.1 | 1960 | 66.68 |
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