Year | Value | 2021 | 78 | 2020 | 79 | 2019 | 79.7 | 2018 | 79.6 | 2017 | 79.3 | 2016 | 79.7 | 2015 | 79 | 2014 | 79.4 | 2013 | 79.1 | 2012 | 78.7 | 2011 | 78.7 | 2010 | 78.1 | 2009 | 77.9 | 2008 | 77.8 | 2007 | 77.3 | 2006 | 77.4 | 2005 | 76.9 | 2004 | 76.9 | 2003 | 76.5 | 2002 | 76.6 | 2001 | 76.5 | 2000 | 75.6 | 1999 | 75.21 | 1998 | 75.186 | 1997 | 75.22 | 1996 | 74.79 | 1995 | 74.55 | 1994 | 74.31 | 1993 | 73.88 | 1992 | 73.86 | 1991 | 73.91 | 1990 | 73.7 | 1989 | 73.8 | 1988 | 74.08 | 1987 | 73.8 | 1986 | 73.23 | 1985 | 73.08 | 1984 | 73.19 | 1983 | 73.02 | 1982 | 73.23 | 1981 | 72.95 | 1980 | 72.77 | 1979 | 73.17 | 1978 | 72.8 | 1977 | 73.08 | 1976 | 72.59 | 1975 | 72.44 | 1974 | 72.27 | 1973 | 72.54 | 1972 | 72.62 | 1971 | 72.1 | 1970 | 72.12 | 1969 | 72.06 | 1968 | 71.95 | 1967 | 72.05 | 1966 | 72.24 | 1965 | 71.54 | 1964 | 71.86 | 1963 | 71.22 | 1962 | 70.14 | 1961 | 71.2 | 1960 | 70.18 |
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