Year | Value | 2021 | 63.692 | 2020 | 63.426 | 2019 | 63.233 | 2018 | 62.996 | 2017 | 62.77 | 2016 | 62.559 | 2015 | 62.307 | 2014 | 62.106 | 2013 | 61.924 | 2012 | 61.827 | 2011 | 61.687 | 2010 | 61.668 | 2009 | 61.672 | 2008 | 61.664 | 2007 | 61.745 | 2006 | 61.811 | 2005 | 61.765 | 2004 | 61.715 | 2003 | 61.663 | 2002 | 61.619 | 2001 | 61.577 | 2000 | 61.253 | 1999 | 61.454 | 1998 | 61.402 | 1997 | 61.307 | 1996 | 61.075 | 1995 | 60.756 | 1994 | 60.462 | 1993 | 60.29 | 1992 | 60.002 | 1991 | 59.714 | 1990 | 59.457 | 1989 | 59.334 | 1988 | 59.143 | 1987 | 59.027 | 1986 | 58.981 | 1985 | 58.853 | 1984 | 58.583 | 1983 | 58.235 | 1982 | 57.889 | 1981 | 57.627 | 1980 | 57.485 | 1979 | 57.388 | 1978 | 57.28 | 1977 | 57.206 | 1976 | 57.086 | 1975 | 56.95 | 1974 | 56.77 | 1973 | 56.55 | 1972 | 56.287 | 1971 | 55.965 | 1970 | 55.601 | 1969 | 55.242 | 1968 | 54.873 | 1967 | 54.459 | 1966 | 54.038 | 1965 | 53.581 | 1964 | 53.11 | 1963 | 52.623 | 1962 | 52.066 | 1961 | 51.513 | 1960 | 51.114 |
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