Year | Value | 2021 | 81.3 | 2020 | 80.3 | 2019 | 81.2 | 2018 | 80.4 | 2017 | 80.2 | 2016 | 80.6 | 2015 | 79.8 | 2014 | 79.9 | 2013 | 79.6 | 2012 | 78.6 | 2011 | 78.6 | 2010 | 79.3 | 2009 | 77.9 | 2008 | 77.1 | 2007 | 77.5 | 2006 | 77 | 2005 | 77.3 | 2004 | 77.4 | 2003 | 76.4 | 2002 | 76.3 | 2001 | 76.6 | 2000 | 76.3 | 1999 | 75.5 | 1998 | 75.1 | 1997 | 75.3 | 1996 | 75 | 1995 | 74.9 | 1994 | 74.734 | 1993 | 73.973 | 1992 | 73.222 | 1991 | 73.154 | 1990 | 73.499 | 1989 | 73.229 | 1988 | 72.813 | 1987 | 72.536 | 1986 | 71.672 | 1985 | 70.371 | 1984 | 71.218 | 1983 | 71.258 | 1982 | 69.542 | 1981 | 70.944 | 1980 | 69.719 | 1979 | 69.865 | 1978 | 70.022 | 1977 | 69.963 | 1976 | 70.043 | 1975 | 69.997 | 1974 | 70.079 | 1973 | 68.457 | 1972 | 68.4 | 1971 | 67.164 | 1970 | 66.568 | 1969 | 66.598 | 1968 | 67.618 | 1967 | 67.561 | 1966 | 67.195 | 1965 | 66.444 | 1964 | 67.26 | 1963 | 66.33 | 1962 | 66.563 | 1961 | 67.458 | 1960 | 66.606 |
|