Year | Value | 2021 | 68.285 | 2020 | 68.426 | 2019 | 68.795 | 2018 | 68.397 | 2017 | 67.533 | 2016 | 67.341 | 2015 | 66.326 | 2014 | 65.361 | 2013 | 64.895 | 2012 | 63.804 | 2011 | 62.874 | 2010 | 61.849 | 2009 | 60.962 | 2008 | 59.416 | 2007 | 58.062 | 2006 | 56.528 | 2005 | 55.338 | 2004 | 54.249 | 2003 | 53.436 | 2002 | 52.317 | 2001 | 51.644 | 2000 | 51.198 | 1999 | 50.777 | 1998 | 50.934 | 1997 | 50.508 | 1996 | 49.872 | 1995 | 49.422 | 1994 | 49.1 | 1993 | 48.711 | 1992 | 48.276 | 1991 | 47.866 | 1990 | 46.758 | 1989 | 47.101 | 1988 | 47.045 | 1987 | 47.304 | 1986 | 39.491 | 1985 | 39.111 | 1984 | 38.351 | 1983 | 37.944 | 1982 | 46.175 | 1981 | 45.937 | 1980 | 45.549 | 1979 | 45.224 | 1978 | 44.561 | 1977 | 44.507 | 1976 | 44.523 | 1975 | 41.604 | 1974 | 41.546 | 1973 | 43.853 | 1972 | 43.717 | 1971 | 45.153 | 1970 | 45.01 | 1969 | 45.127 | 1968 | 45.144 | 1967 | 44.99 | 1966 | 42.323 | 1965 | 44.77 | 1964 | 44.708 | 1963 | 44.309 | 1962 | 43.76 | 1961 | 43.367 | 1960 | 42.676 |
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