Year | Value | 2024 | 50.146604470914 | 2023 | 50.135270030531 | 2022 | 50.12142883099 | 2021 | 50.104127076335 | 2020 | 50.087539036412 | 2019 | 50.07009249412 | 2018 | 50.047535613756 | 2017 | 50.022579314358 | 2016 | 49.995473523704 | 2015 | 49.965182544955 | 2014 | 49.932388957646 | 2013 | 49.897066291251 | 2012 | 49.859886703322 | 2011 | 49.823309231977 | 2010 | 49.787026955084 | 2009 | 49.749506358062 | 2008 | 49.710396072327 | 2007 | 49.667538496057 | 2006 | 49.621177001629 | 2005 | 49.597437404041 | 2004 | 49.575964000909 | 2003 | 49.532349703421 | 2002 | 49.489409447762 | 2001 | 49.447216851411 | 2000 | 49.404877216591 | 1999 | 49.361949626843 | 1998 | 49.317584872735 | 1997 | 49.268937693717 | 1996 | 49.218020800838 | 1995 | 49.171079332919 | 1994 | 49.131600953071 | 1993 | 49.079061679573 | 1992 | 49.02159067101 | 1991 | 48.979562986937 | 1990 | 48.938848379403 | 1989 | 48.899848447515 | 1988 | 48.86142281382 | 1987 | 48.822929027915 | 1986 | 48.785242823105 | 1985 | 48.747931913798 | 1984 | 48.709546802533 | 1983 | 48.669658969969 | 1982 | 48.627615330522 | 1981 | 48.582847073576 | 1980 | 48.535902544831 | 1979 | 48.487899001919 | 1978 | 48.439813302029 | 1977 | 48.391036436831 | 1976 | 48.339687735424 | 1975 | 48.284484242355 |
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