Year | Value | 2021 | 81.232 | 2020 | 81.264 | 2019 | 81.39 | 2018 | 81.375 | 2017 | 81.331 | 2016 | 81.366 | 2015 | 81.433 | 2014 | 81.884 | 2013 | 81.516 | 2012 | 81.339 | 2011 | 81.726 | 2010 | 81.12 | 2009 | 80.995 | 2008 | 81.317 | 2007 | 81.166 | 2006 | 80.694 | 2005 | 80.344 | 2004 | 80.125 | 2003 | 79.618 | 2002 | 78.906 | 2001 | 79.277 | 2000 | 79.155 | 1999 | 78.935 | 1998 | 78.898 | 1997 | 78.211 | 1996 | 77.962 | 1995 | 77.749 | 1994 | 78.005 | 1993 | 76.547 | 1992 | 78.125 | 1991 | 76.617 | 1990 | 77.185 | 1989 | 77.211 | 1988 | 77.045 | 1987 | 76.623 | 1986 | 75.616 | 1985 | 75.266 | 1984 | 76.076 | 1983 | 74.041 | 1982 | 74.87 | 1981 | 73.858 | 1980 | 73.428 | 1979 | 72.509 | 1978 | 73.211 | 1977 | 72.833 | 1976 | 72.57 | 1975 | 71.651 | 1974 | 72.237 | 1973 | 72.148 | 1972 | 71.868 | 1971 | 71.685 | 1970 | 71.165 | 1969 | 71.508 | 1968 | 71.206 | 1967 | 73.235 | 1966 | 72.366 | 1965 | 72.031 | 1964 | 72.476 | 1963 | 70.305 | 1962 | 72.043 | 1961 | 69.747 | 1960 | 71.47 |
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