Year | Value | 2021 | 69.531463606727 | 2020 | 69.76362996243 | 2019 | 70.754434235157 | 2018 | 70.513847369502 | 2017 | 70.204440119255 | 2016 | 69.743159198602 | 2015 | 69.634847760401 | 2014 | 69.295884696454 | 2013 | 68.972508903847 | 2012 | 68.9768743351 | 2011 | 69.213096790141 | 2010 | 69.008925336173 | 2009 | 68.807330560992 | 2008 | 68.415961218354 | 2007 | 67.997477254781 | 2006 | 67.66395890618 | 2005 | 67.621498596565 | 2004 | 67.389092250381 | 2003 | 66.975595815256 | 2002 | 67.225301619374 | 2001 | 66.868905515158 | 2000 | 66.538049902135 | 1999 | 66.265076632381 | 1998 | 65.868573940336 | 1997 | 65.601319012885 | 1996 | 65.338162499272 | 1995 | 64.973689674862 | 1994 | 64.662864300917 | 1993 | 64.616896709646 | 1992 | 64.282498917568 | 1991 | 63.651259345072 | 1990 | 62.356368803243 | 1989 | 62.363233962267 | 1988 | 60.964824415181 | 1987 | 60.62738114589 | 1986 | 59.722855297734 | 1985 | 59.278235988106 | 1984 | 58.500598583639 | 1983 | 56.871934107021 | 1982 | 55.256219904525 | 1981 | 54.927617537583 | 1980 | 55.670938836405 | 1979 | 55.719476541144 | 1978 | 54.598369750744 | 1977 | 54.090296561445 | 1976 | 52.782737959676 | 1975 | 52.291679287879 | 1974 | 51.812356225582 | 1973 | 50.991782301141 | 1972 | 50.640094204565 | 1971 | 50.07544210543 | 1970 | 49.400045678032 | 1969 | 48.850860015044 | 1968 | 48.295711476464 | 1967 | 47.85159711402 | 1966 | 47.434464413251 | 1965 | 46.989986493056 | 1964 | 46.39421213579 | 1963 | 45.696742897805 | 1962 | 44.349759174165 | 1961 | 44.116032663804 | 1960 | 43.422953747216 |
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