Year | Value | 2021 | 79.5 | 2020 | 78.5 | 2019 | 79.8 | 2018 | 79.4 | 2017 | 79.2 | 2016 | 79 | 2015 | 78.7 | 2014 | 78.8 | 2013 | 78.1 | 2012 | 77.8 | 2011 | 78 | 2010 | 77.5 | 2009 | 77.4 | 2008 | 76.9 | 2007 | 77.1 | 2006 | 76.6 | 2005 | 76.2 | 2004 | 76 | 2003 | 75.3 | 2002 | 75.1 | 2001 | 74.9 | 2000 | 74.6 | 1999 | 74.4 | 1998 | 74.4 | 1997 | 74.2 | 1996 | 73.88 | 1995 | 73.47 | 1994 | 73.36 | 1993 | 72.96 | 1992 | 73 | 1991 | 72.88 | 1990 | 72.73 | 1989 | 72.34 | 1988 | 72.2 | 1987 | 72 | 1986 | 71.4 | 1985 | 71.13 | 1984 | 71 | 1983 | 70.63 | 1982 | 70.61 | 1981 | 70.29 | 1980 | 69.89 | 1979 | 69.94 | 1978 | 69.42 | 1977 | 69.53 | 1976 | 68.91 | 1975 | 68.82 | 1974 | 68.82 | 1973 | 68.45 | 1972 | 68.21 | 1971 | 67.88 | 1970 | 67.85 | 1969 | 67.56 | 1968 | 67.62 | 1967 | 67.93 | 1966 | 67.76 | 1965 | 67.64 | 1964 | 67.76 | 1963 | 67.11 | 1962 | 67.4 | 1961 | 67.56 | 1960 | 66.78 |
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