Year | Value | 2021 | 67.9 | 2020 | 67.8 | 2019 | 67.6 | 2018 | 67.4 | 2017 | 67.2 | 2016 | 67 | 2015 | 66.7 | 2014 | 66.5 | 2013 | 66.3 | 2012 | 66.1 | 2011 | 65.7 | 2010 | 65.3 | 2009 | 65.2 | 2008 | 64.5 | 2007 | 63.7 | 2006 | 63.5 | 2005 | 64.2 | 2004 | 64.3 | 2003 | 64.5 | 2002 | 64.4 | 2001 | 65 | 2000 | 64.9 | 1999 | 64.9 | 1998 | 63.1 | 1997 | 62.6 | 1996 | 62.3 | 1995 | 61.4 | 1994 | 61.6 | 1993 | 62.9 | 1992 | 64.2 | 1991 | 64.6 | 1990 | 64.2 | 1989 | 64.2 | 1988 | 60.633 | 1987 | 60.438 | 1986 | 60.047 | 1985 | 59.54 | 1984 | 58.989 | 1983 | 58.76 | 1982 | 58.472 | 1981 | 57.957 | 1980 | 57.6 | 1979 | 57.456 | 1978 | 56.98 | 1977 | 56.67 | 1976 | 56.329 | 1975 | 55.972 | 1974 | 55.589 | 1973 | 55.278 | 1972 | 54.925 | 1971 | 54.681 | 1970 | 54.258 | 1969 | 53.993 | 1968 | 53.716 | 1967 | 53.387 | 1966 | 53.016 | 1965 | 52.709 | 1964 | 52.474 | 1963 | 52.175 | 1962 | 51.886 | 1961 | 51.599 | 1960 | 51.304 |
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