Year | Value | 2021 | 79.28 | 2020 | 81.136 | 2019 | 81.033 | 2018 | 80.825 | 2017 | 82.351 | 2016 | 80.608 | 2015 | 80.918 | 2014 | 79.518 | 2013 | 79.992 | 2012 | 81.272 | 2011 | 81.403 | 2010 | 80.499 | 2009 | 79.996 | 2008 | 78.623 | 2007 | 79.361 | 2006 | 77.585 | 2005 | 77.927 | 2004 | 81.12 | 2003 | 79.345 | 2002 | 80.631 | 2001 | 79.871 | 2000 | 78.858 | 1999 | 79.053 | 1998 | 79.949 | 1997 | 77.995 | 1996 | 78.225 | 1995 | 76.137 | 1994 | 73.608 | 1993 | 74.487 | 1992 | 73.8 | 1991 | 74.886 | 1990 | 74.5 | 1989 | 74.269 | 1988 | 74.91 | 1987 | 73.996 | 1986 | 73.428 | 1985 | 73.337 | 1984 | 74.526 | 1983 | 74.116 | 1982 | 73.746 | 1981 | 73.684 | 1980 | 73.454 | 1979 | 73.299 | 1978 | 72.854 | 1977 | 72.083 | 1976 | 71.862 | 1975 | 72.573 | 1974 | 72.394 | 1973 | 71.888 | 1972 | 69.961 | 1971 | 68.502 | 1970 | 69.478 | 1969 | 68.211 | 1968 | 68.535 | 1967 | 68.358 | 1966 | 63.426 | 1965 | 67.848 | 1964 | 67.641 | 1963 | 63.778 | 1962 | 63.837 | 1961 | 64.111 | 1960 | 67.162 |
|