Year | Value | 2021 | 65.893976328847 | 2020 | 68.04436004102 | 2019 | 68.872210235854 | 2018 | 68.705928464945 | 2017 | 68.435890581131 | 2016 | 68.090015490837 | 2015 | 67.594448923899 | 2014 | 67.027693316728 | 2013 | 66.420398764599 | 2012 | 65.933935408715 | 2011 | 65.462149491557 | 2010 | 65.078083070623 | 2009 | 64.620714239661 | 2008 | 64.345081761552 | 2007 | 64.10843936223 | 2006 | 63.92689744859 | 2005 | 63.584068500711 | 2004 | 63.299165834718 | 2003 | 63.040120371636 | 2002 | 62.70203507909 | 2001 | 62.30969894674 | 2000 | 61.975819911748 | 1999 | 61.720964205517 | 1998 | 61.144300216698 | 1997 | 60.626825687769 | 1996 | 60.213759611831 | 1995 | 59.824757122587 | 1994 | 59.457565075528 | 1993 | 59.07711417154 | 1992 | 58.684762916188 | 1991 | 58.049337710005 | 1990 | 57.889966240325 | 1989 | 57.424830545469 | 1988 | 57.061687204089 | 1987 | 56.696330439334 | 1986 | 56.346491357081 | 1985 | 55.817263509915 | 1984 | 55.387104244809 | 1983 | 54.999451137553 | 1982 | 54.536881102508 | 1981 | 54.122058767453 | 1980 | 53.668484939612 | 1979 | 53.250512763595 | 1978 | 52.889473782251 | 1977 | 52.495119570943 | 1976 | 52.145394475416 | 1975 | 51.695017365551 | 1974 | 51.155454666734 | 1973 | 50.668777276058 | 1972 | 50.212543433768 | 1971 | 46.720155001467 | 1970 | 48.914638321655 | 1969 | 49.024461021519 | 1968 | 48.631410633879 | 1967 | 47.085849626962 | 1966 | 46.706996974676 | 1965 | 46.163015200624 | 1964 | 47.13090767187 | 1963 | 46.755282229884 | 1962 | 46.441735111914 | 1961 | 46.049930223643 | 1960 | 45.732487280236 |
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