Year | Value | 2021 | 73.734 | 2020 | 70.17 | 2019 | 73.01 | 2018 | 72.599 | 2017 | 72.34 | 2016 | 72.088 | 2015 | 71.868 | 2014 | 71.644 | 2013 | 71.334 | 2012 | 70.949 | 2011 | 70.824 | 2010 | 70.353 | 2009 | 70.507 | 2008 | 70.109 | 2007 | 69.697 | 2006 | 69.536 | 2005 | 68.995 | 2004 | 68.534 | 2003 | 67.913 | 2002 | 67.251 | 2001 | 66.395 | 2000 | 65.956 | 1999 | 65.266 | 1998 | 64.523 | 1997 | 63.425 | 1996 | 62.446 | 1995 | 62.785 | 1994 | 62.377 | 1993 | 62.085 | 1992 | 62.281 | 1991 | 64.218 | 1990 | 64.559 | 1989 | 64.533 | 1988 | 64.373 | 1987 | 63.463 | 1986 | 63.115 | 1985 | 62.863 | 1984 | 62.546 | 1983 | 62.186 | 1982 | 61.957 | 1981 | 61.739 | 1980 | 61.729 | 1979 | 61.87 | 1978 | 61.678 | 1977 | 61.541 | 1976 | 61.293 | 1975 | 60.993 | 1974 | 60.623 | 1973 | 60.109 | 1972 | 60.026 | 1971 | 59.645 | 1970 | 59.241 | 1969 | 58.942 | 1968 | 58.458 | 1967 | 58.121 | 1966 | 57.795 | 1965 | 57.425 | 1964 | 57.261 | 1963 | 56.925 | 1962 | 56.673 | 1961 | 56.367 | 1960 | 56.063 |
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