Year | Value | 2021 | 83.1 | 2020 | 83.1 | 2019 | 83.7 | 2018 | 83.4 | 2017 | 83.4 | 2016 | 83.2 | 2015 | 83.2 | 2014 | 83.5 | 2013 | 83.2 | 2012 | 83 | 2011 | 83.1 | 2010 | 82.7 | 2009 | 82.7 | 2008 | 82.3 | 2007 | 82.3 | 2006 | 81.9 | 2005 | 81.6 | 2004 | 81.4 | 2003 | 80.9 | 2002 | 80.7 | 2001 | 80.7 | 2000 | 80.6 | 1999 | 80.5 | 1998 | 80.7 | 1997 | 80.55 | 1996 | 80.35 | 1995 | 80.36 | 1994 | 80.31 | 1993 | 80 | 1992 | 80.28 | 1991 | 80.15 | 1990 | 80.11 | 1989 | 79.92 | 1988 | 80.24 | 1987 | 80.06 | 1986 | 79.61 | 1985 | 79.66 | 1984 | 79.67 | 1983 | 79.56 | 1982 | 79.41 | 1981 | 79.32 | 1980 | 79.18 | 1979 | 78.92 | 1978 | 78.5 | 1977 | 78.52 | 1976 | 77.92 | 1975 | 77.7 | 1974 | 77.61 | 1973 | 77.13 | 1972 | 76.79 | 1971 | 76.77 | 1970 | 76.5 | 1969 | 76.29 | 1968 | 76.44 | 1967 | 76.57 | 1966 | 76.12 | 1965 | 76.14 | 1964 | 76.26 | 1963 | 75.77 | 1962 | 75.68 | 1961 | 75.85 | 1960 | 75.38 |
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