Year | Value | 2021 | 57.4 | 2020 | 57.86 | 2019 | 58.162 | 2018 | 57.846 | 2017 | 57.348 | 2016 | 57.13 | 2015 | 56.677 | 2014 | 56.234 | 2013 | 55.581 | 2012 | 55.073 | 2011 | 54.398 | 2010 | 53.936 | 2009 | 53.297 | 2008 | 52.629 | 2007 | 52.02 | 2006 | 51.392 | 2005 | 50.822 | 2004 | 50.306 | 2003 | 49.745 | 2002 | 49.707 | 2001 | 49.547 | 2000 | 49.464 | 1999 | 49.537 | 1998 | 49.439 | 1997 | 49.617 | 1996 | 49.444 | 1995 | 49.521 | 1994 | 49.665 | 1993 | 49.899 | 1992 | 50.109 | 1991 | 50.304 | 1990 | 50.609 | 1989 | 50.926 | 1988 | 51.056 | 1987 | 51.218 | 1986 | 51.279 | 1985 | 51.298 | 1984 | 51.163 | 1983 | 51.117 | 1982 | 50.88 | 1981 | 50.693 | 1980 | 50.36 | 1979 | 49.819 | 1978 | 49.112 | 1977 | 48.502 | 1976 | 47.671 | 1975 | 46.866 | 1974 | 46.062 | 1973 | 45.188 | 1972 | 44.36 | 1971 | 43.61 | 1970 | 42.936 | 1969 | 42.243 | 1968 | 41.627 | 1967 | 40.939 | 1966 | 40.359 | 1965 | 39.682 | 1964 | 39.067 | 1963 | 38.407 | 1962 | 37.868 | 1961 | 37.21 | 1960 | 36.525 |
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