Year | Value | 2021 | 74.77 | 2020 | 76.43 | 2019 | 78.17 | 2018 | 77.82 | 2017 | 77.64 | 2016 | 77.06 | 2015 | 76.71 | 2014 | 76.47 | 2013 | 76.3 | 2012 | 75.86 | 2011 | 75.61 | 2010 | 74.88 | 2009 | 74.79 | 2008 | 74.28 | 2007 | 74.02 | 2006 | 73.34 | 2005 | 72.47 | 2004 | 72.36 | 2003 | 71.85 | 2002 | 71.9 | 2001 | 72.17 | 2000 | 72.26 | 1999 | 72.4 | 1998 | 73.13 | 1997 | 72.84 | 1996 | 72.4 | 1995 | 71.59 | 1994 | 71.73 | 1993 | 71.2 | 1992 | 71.99 | 1991 | 73.75 | 1990 | 74.3 | 1989 | 74.35 | 1988 | 74.53 | 1987 | 74.27 | 1986 | 74.23 | 1985 | 73.24 | 1984 | 72.97 | 1983 | 73.42 | 1982 | 73.64 | 1981 | 73.19 | 1980 | 72.96 | 1979 | 73.02 | 1978 | 73.23 | 1977 | 73.2 | 1976 | 73.05 | 1975 | 73.23 | 1974 | 73.77 | 1973 | 73.56 | 1972 | 73.62 | 1971 | 73.77 | 1970 | 73.44 | 1969 | 71.925 | 1968 | 72.43 | 1967 | 72.327 | 1966 | 72.576 | 1965 | 72.371 | 1964 | 72.686 | 1963 | 72.097 | 1962 | 71.647 | 1961 | 71.98 | 1960 | 71.74 |
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