Year | Value | 2021 | 75.859860809153 | 2020 | 76.091486529316 | 2019 | 77.581257307903 | 2018 | 77.379911161471 | 2017 | 77.307953612554 | 2016 | 77.250033907448 | 2015 | 77.152118193054 | 2014 | 77.252009773513 | 2013 | 76.990555190774 | 2012 | 76.766803536509 | 2011 | 76.571791867203 | 2010 | 76.333985868909 | 2009 | 76.132741157571 | 2008 | 75.847804072719 | 2007 | 75.661701007598 | 2006 | 75.438528212995 | 2005 | 75.137995294535 | 2004 | 75.00150936979 | 2003 | 74.590189526247 | 2002 | 74.426668074024 | 2001 | 74.216311990208 | 2000 | 73.891493525748 | 1999 | 73.485955063081 | 1998 | 73.30816327254 | 1997 | 73.062818675277 | 1996 | 72.676874514798 | 1995 | 72.222927309934 | 1994 | 72.10234919936 | 1993 | 71.821452527463 | 1992 | 71.67504839858 | 1991 | 71.399307714666 | 1990 | 71.207376842204 | 1989 | 71.099563457795 | 1988 | 70.877527845923 | 1987 | 70.743230604912 | 1986 | 70.454570500726 | 1985 | 70.118720224574 | 1984 | 70.012519299766 | 1983 | 69.718024614938 | 1982 | 69.56863050273 | 1981 | 69.2011328549 | 1980 | 68.802880395558 | 1979 | 68.698240111489 | 1978 | 68.370965047024 | 1977 | 68.227827450988 | 1976 | 67.870496607843 | 1975 | 67.613489640235 | 1974 | 67.374111344905 | 1973 | 66.98678745182 | 1972 | 66.823414918335 | 1971 | 66.590566289535 | 1970 | 66.33628065643 | 1969 | 66.041822246922 | 1968 | 65.883541764615 | 1967 | 66.107030404643 | 1966 | 65.824411349424 | 1965 | 65.619010024169 | 1964 | 65.50319885091 | 1963 | 65.092558327878 | 1962 | 64.945604082457 | 1961 | 64.971332563811 | 1960 | 64.558241510156 |
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