Year | Value | 2021 | 64.92 | 2020 | 64.898 | 2019 | 64.99 | 2018 | 64.744 | 2017 | 64.028 | 2016 | 63.809 | 2015 | 63.005 | 2014 | 62.259 | 2013 | 61.848 | 2012 | 60.76 | 2011 | 59.722 | 2010 | 58.768 | 2009 | 58.183 | 2008 | 57.337 | 2007 | 56.719 | 2006 | 55.885 | 2005 | 54.269 | 2004 | 52.832 | 2003 | 51.913 | 2002 | 51.578 | 2001 | 51.093 | 2000 | 50.62 | 1999 | 50.186 | 1998 | 49.601 | 1997 | 49.299 | 1996 | 49.099 | 1995 | 48.85 | 1994 | 48.637 | 1993 | 48.381 | 1992 | 48.695 | 1991 | 48.789 | 1990 | 48.992 | 1989 | 49.29 | 1988 | 49.608 | 1987 | 49.611 | 1986 | 49.622 | 1985 | 49.763 | 1984 | 48.601 | 1983 | 48.433 | 1982 | 48.142 | 1981 | 47.421 | 1980 | 47.392 | 1979 | 48.482 | 1978 | 48.783 | 1977 | 48.442 | 1976 | 48.793 | 1975 | 49.236 | 1974 | 50.169 | 1973 | 49.855 | 1972 | 50.619 | 1971 | 50.6 | 1970 | 52.427 | 1969 | 52.288 | 1968 | 51.94 | 1967 | 51.667 | 1966 | 51.085 | 1965 | 50.923 | 1964 | 50.436 | 1963 | 49.93 | 1962 | 49.485 | 1961 | 48.697 | 1960 | 47.949 |
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