Year | Value | 2022 | 49.917618067453 | 2021 | 49.914803872084 | 2020 | 49.905982609005 | 2019 | 49.900800432279 | 2018 | 49.903637173652 | 2017 | 49.903311728449 | 2016 | 49.895440365111 | 2015 | 49.890674482852 | 2014 | 49.888572168956 | 2013 | 49.884744054678 | 2012 | 49.880074981237 | 2011 | 49.869878768931 | 2010 | 49.845089697491 | 2009 | 49.81241685224 | 2008 | 49.782312177885 | 2007 | 49.753462467163 | 2006 | 49.724948315297 | 2005 | 49.69625731152 | 2004 | 49.666726875066 | 2003 | 49.636027390413 | 2002 | 49.606391405364 | 2001 | 49.575572898853 | 2000 | 49.542677621734 | 1999 | 49.508694718763 | 1998 | 49.473465550041 | 1997 | 49.439591919962 | 1996 | 49.408448079558 | 1995 | 49.381274509577 | 1994 | 49.356499661316 | 1993 | 49.330254992215 | 1992 | 49.323508108648 | 1991 | 49.346420360899 | 1990 | 49.37603043754 | 1989 | 49.401099805554 | 1988 | 49.423939082373 | 1987 | 49.449088171057 | 1986 | 49.476626412678 | 1985 | 49.502230532047 | 1984 | 49.526871739861 | 1983 | 49.549879360036 | 1982 | 49.614565364457 | 1981 | 49.769780403685 | 1980 | 49.971074313254 | 1979 | 50.172495685747 | 1978 | 50.373282126586 | 1977 | 50.575246719296 | 1976 | 50.780127853431 | 1975 | 50.873977878452 | 1974 | 50.666142448561 | 1973 | 50.454507034678 | 1972 | 50.440999351471 | 1971 | 50.4528927877 | 1970 | 50.47705694721 | 1969 | 50.509326796698 | 1968 | 50.547393319967 | 1967 | 50.589378599479 | 1966 | 50.633989006788 | 1965 | 50.670532684318 | 1964 | 50.68850863412 | 1963 | 50.701564229614 | 1962 | 50.723928829886 | 1961 | 50.749279974982 | 1960 | 50.765803064578 |
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