Year | Value | 2022 | 49.513030023117 | 2021 | 49.505808792456 | 2020 | 49.499063326304 | 2019 | 49.494982940012 | 2018 | 49.491690151316 | 2017 | 49.488391674225 | 2016 | 49.487403975143 | 2015 | 49.485954960184 | 2014 | 49.483643115179 | 2013 | 49.481337750874 | 2012 | 49.481083111051 | 2011 | 49.482753267604 | 2010 | 49.483684941273 | 2009 | 49.48546279478 | 2008 | 49.488111462508 | 2007 | 49.490579871531 | 2006 | 49.492426381658 | 2005 | 49.494190341511 | 2004 | 49.496757174074 | 2003 | 49.501331411466 | 2002 | 49.50928914568 | 2001 | 49.522964091996 | 2000 | 49.543642325129 | 1999 | 49.568915176551 | 1998 | 49.594759179792 | 1997 | 49.61994057321 | 1996 | 49.647499690581 | 1995 | 49.672989692467 | 1994 | 49.69025814687 | 1993 | 49.702803657704 | 1992 | 49.717847625259 | 1991 | 49.737214144415 | 1990 | 49.75549540046 | 1989 | 49.773926097677 | 1988 | 49.790878394295 | 1987 | 49.805323819738 | 1986 | 49.822402739044 | 1985 | 49.840534238697 | 1984 | 49.85704410369 | 1983 | 49.872875493518 | 1982 | 49.885185819926 | 1981 | 49.892457901802 | 1980 | 49.895945531151 | 1979 | 49.892596077156 | 1978 | 49.883075463124 | 1977 | 49.869234886385 | 1976 | 49.851519937576 | 1975 | 49.829355465657 | 1974 | 49.803410514375 | 1973 | 49.777011201878 | 1972 | 49.752487648803 | 1971 | 49.730532510398 | 1970 | 49.709689649305 | 1969 | 49.686873325982 | 1968 | 49.662088981784 | 1967 | 49.63553517986 | 1966 | 49.607410361914 | 1965 | 49.575945160487 | 1964 | 49.543221812593 | 1963 | 49.510579194329 | 1962 | 49.473825012352 | 1961 | 49.434260099217 | 1960 | 49.393056621615 |
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