Year | Value | 2021 | 68.346 | 2020 | 68.322 | 2019 | 68.294 | 2018 | 68.206 | 2017 | 68.212 | 2016 | 68.036 | 2015 | 67.114 | 2014 | 67.472 | 2013 | 68.128 | 2012 | 68.812 | 2011 | 68.722 | 2010 | 68.376 | 2009 | 68.129 | 2008 | 68.265 | 2007 | 68.365 | 2006 | 68.453 | 2005 | 68.309 | 2004 | 67.755 | 2003 | 67.378 | 2002 | 67.447 | 2001 | 67.673 | 2000 | 67.348 | 1999 | 66.445 | 1998 | 65.216 | 1997 | 65.192 | 1996 | 64.704 | 1995 | 64.391 | 1994 | 64.602 | 1993 | 64.983 | 1992 | 64.27 | 1991 | 63.656 | 1990 | 62.778 | 1989 | 62.464 | 1988 | 62.917 | 1987 | 62.667 | 1986 | 62.593 | 1985 | 62.747 | 1984 | 62.853 | 1983 | 62.869 | 1982 | 62.335 | 1981 | 61.411 | 1980 | 60.316 | 1979 | 60.355 | 1978 | 60.159 | 1977 | 60.299 | 1976 | 59.905 | 1975 | 59.691 | 1974 | 58.547 | 1973 | 57.301 | 1972 | 57.135 | 1971 | 57.69 | 1970 | 58.497 | 1969 | 58.539 | 1968 | 58.695 | 1967 | 58.279 | 1966 | 57.779 | 1965 | 57.4 | 1964 | 57.228 | 1963 | 56.99 | 1962 | 55.506 | 1961 | 53.982 | 1960 | 54.349 |
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