Year | Value | 2021 | 80.2 | 2020 | 80.8 | 2019 | 80.8 | 2018 | 80.4 | 2017 | 80.4 | 2016 | 79.8 | 2015 | 79.6 | 2014 | 79.3 | 2013 | 78.9 | 2012 | 78.7 | 2011 | 78.6 | 2010 | 78.5 | 2009 | 77.8 | 2008 | 77.9 | 2007 | 77.3 | 2006 | 76.9 | 2005 | 76.7 | 2004 | 76.1 | 2003 | 75.7 | 2002 | 75 | 2001 | 74.5 | 2000 | 74 | 1999 | 73.4 | 1998 | 73.4 | 1997 | 73.4 | 1996 | 73.1 | 1995 | 72.762 | 1994 | 73.052 | 1993 | 72.56 | 1992 | 72.679 | 1991 | 72.285 | 1990 | 72.109 | 1989 | 71.744 | 1988 | 71.696 | 1987 | 71.648 | 1986 | 70.847 | 1985 | 70.758 | 1984 | 70.913 | 1983 | 70.404 | 1982 | 70.471 | 1981 | 70.163 | 1980 | 69.932 | 1979 | 69.389 | 1978 | 69.349 | 1977 | 69.493 | 1976 | 69.361 | 1975 | 69.175 | 1974 | 68.638 | 1973 | 68.719 | 1972 | 68.592 | 1971 | 69.29 | 1970 | 68.584 | 1969 | 68.726 | 1968 | 68.721 | 1967 | 69.08 | 1966 | 68.095 | 1965 | 68.555 | 1964 | 68.487 | 1963 | 68.294 | 1962 | 67.973 | 1961 | 67.85 | 1960 | 68.485 |
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