Year | Value | 2022 | 48.969037165943 | 2021 | 48.940753578669 | 2020 | 48.910201140641 | 2019 | 48.88527326422 | 2018 | 48.865734576676 | 2017 | 48.846832464293 | 2016 | 48.832309865615 | 2015 | 48.823119954397 | 2014 | 48.816960277818 | 2013 | 48.813663807421 | 2012 | 48.812498515525 | 2011 | 48.81291466035 | 2010 | 48.814400137889 | 2009 | 48.817750959349 | 2008 | 48.822464603524 | 2007 | 48.827197888108 | 2006 | 48.832469702662 | 2005 | 48.838083414883 | 2004 | 48.843393490169 | 2003 | 48.848932883567 | 2002 | 48.854654240324 | 2001 | 48.860837110352 | 2000 | 48.872174115967 | 1999 | 48.889584678798 | 1998 | 48.905145155385 | 1997 | 48.920160174186 | 1996 | 48.938003634158 | 1995 | 48.955925444591 | 1994 | 48.974353667906 | 1993 | 48.992313919571 | 1992 | 49.010046971178 | 1991 | 49.030144226974 | 1990 | 49.051239693273 | 1989 | 49.069300293275 | 1988 | 49.082268967631 | 1987 | 49.092246271587 | 1986 | 49.099931637303 | 1985 | 49.104045528545 | 1984 | 49.104810535383 | 1983 | 49.102838505562 | 1982 | 49.100227580889 | 1981 | 49.097237080023 | 1980 | 49.092564245383 | 1979 | 49.086961694369 | 1978 | 49.080344952493 | 1977 | 49.073067947124 | 1976 | 49.066202623084 | 1975 | 49.059567634141 | 1974 | 49.053555562662 | 1973 | 49.049988743859 | 1972 | 49.0484286003 | 1971 | 49.047440668202 | 1970 | 49.045448005248 | 1969 | 49.04096818938 | 1968 | 49.034165446099 | 1967 | 49.023621697935 | 1966 | 49.009220545734 | 1965 | 48.991569480169 | 1964 | 48.971474729413 | 1963 | 48.950903467812 | 1962 | 48.927293281904 | 1961 | 48.896749716502 | 1960 | 48.860090173529 |
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