Year | Value | 2021 | 66.87 | 2020 | 67.612 | 2019 | 68.21 | 2018 | 67.432 | 2017 | 67.243 | 2016 | 67.136 | 2015 | 66.346 | 2014 | 66.356 | 2013 | 66.231 | 2012 | 65.476 | 2011 | 65.433 | 2010 | 64.606 | 2009 | 64.416 | 2008 | 63.7 | 2007 | 63.398 | 2006 | 62.719 | 2005 | 61.884 | 2004 | 61.532 | 2003 | 60.548 | 2002 | 59.863 | 2001 | 59.449 | 2000 | 58.919 | 1999 | 58.493 | 1998 | 58.287 | 1997 | 57.717 | 1996 | 57.282 | 1995 | 56.623 | 1994 | 55.965 | 1993 | 55.368 | 1992 | 54.456 | 1991 | 53.768 | 1990 | 53.115 | 1989 | 52.478 | 1988 | 52.005 | 1987 | 51.607 | 1986 | 51.104 | 1985 | 50.941 | 1984 | 50.835 | 1983 | 50.854 | 1982 | 50.906 | 1981 | 50.988 | 1980 | 51.062 | 1979 | 51.063 | 1978 | 50.995 | 1977 | 50.865 | 1976 | 50.7 | 1975 | 50.49 | 1974 | 50.123 | 1973 | 49.672 | 1972 | 49.166 | 1971 | 48.832 | 1970 | 48.381 | 1969 | 47.977 | 1968 | 47.516 | 1967 | 46.947 | 1966 | 46.544 | 1965 | 46.209 | 1964 | 45.838 | 1963 | 45.463 | 1962 | 45.084 | 1961 | 44.679 | 1960 | 44.314 |
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