Year | Value | 2021 | 78.8 | 2020 | 78.9 | 2019 | 79.7 | 2018 | 79.4 | 2017 | 79.4 | 2016 | 79.3 | 2015 | 78.8 | 2014 | 79.1 | 2013 | 78.6 | 2012 | 78.4 | 2011 | 78.3 | 2010 | 77.8 | 2009 | 77.6 | 2008 | 77.7 | 2007 | 77.4 | 2006 | 77.1 | 2005 | 76.6 | 2004 | 76.4 | 2003 | 75.9 | 2002 | 75.8 | 2001 | 75.6 | 2000 | 75.2 | 1999 | 74.9 | 1998 | 74.5 | 1997 | 74.1 | 1996 | 73.7 | 1995 | 73.4 | 1994 | 73.2 | 1993 | 72.8 | 1992 | 72.5 | 1991 | 72.3 | 1990 | 72.3 | 1989 | 71.9 | 1988 | 71.9 | 1987 | 71.5 | 1986 | 71 | 1985 | 70.4 | 1984 | 70.1 | 1983 | 69.5 | 1982 | 69.4 | 1981 | 69.3 | 1980 | 69 | 1979 | 68.8 | 1978 | 68.5 | 1977 | 68.5 | 1976 | 68.2 | 1975 | 67.7 | 1974 | 67.5 | 1973 | 67.6 | 1972 | 67 | 1971 | 66.7 | 1970 | 66.5 | 1969 | 66.56 | 1968 | 66.76 | 1967 | 66.63 | 1966 | 66.88 | 1965 | 66.61 | 1964 | 66.8 | 1963 | 66.39 | 1962 | 66.29 | 1961 | 66.47 | 1960 | 65.41 |
|