Year | Value | 2022 | 50.25210017166 | 2021 | 50.249866782445 | 2020 | 50.253037171043 | 2019 | 50.253102949756 | 2018 | 50.249134404213 | 2017 | 50.247818089166 | 2016 | 50.249621176172 | 2015 | 50.249811138526 | 2014 | 50.244598136205 | 2013 | 50.235224917157 | 2012 | 50.224729462252 | 2011 | 50.214467335228 | 2010 | 50.203877561697 | 2009 | 50.188701106609 | 2008 | 50.16513859553 | 2007 | 50.141685921156 | 2006 | 50.119905138127 | 2005 | 50.098876024543 | 2004 | 50.083162463684 | 2003 | 50.06952719714 | 2002 | 50.0568162698 | 2001 | 50.044724134498 | 2000 | 50.03499174292 | 1999 | 50.025139849445 | 1998 | 50.009691885384 | 1997 | 49.99524296095 | 1996 | 49.982177097858 | 1995 | 49.969631375544 | 1994 | 49.962683650735 | 1993 | 49.962915844998 | 1992 | 49.967552756189 | 1991 | 49.974232735485 | 1990 | 49.981580018998 | 1989 | 49.986208691468 | 1988 | 49.982082770728 | 1987 | 49.976047547018 | 1986 | 49.974537404266 | 1985 | 49.972501780108 | 1984 | 49.968188145621 | 1983 | 49.963047214467 | 1982 | 49.959556577857 | 1981 | 49.954721621861 | 1980 | 49.948774089852 | 1979 | 49.940009347731 | 1978 | 49.928258814478 | 1977 | 49.918134074994 | 1976 | 49.908302625105 | 1975 | 49.889919769994 | 1974 | 49.879930526527 | 1973 | 49.882800959852 | 1972 | 49.882709363331 | 1971 | 49.839865639522 | 1970 | 49.796961175403 | 1969 | 49.79707198155 | 1968 | 49.795987116066 | 1967 | 49.794049181881 | 1966 | 49.79099020534 | 1965 | 49.787440132316 | 1964 | 49.783657820236 | 1963 | 49.779467683192 | 1962 | 49.775070031861 | 1961 | 49.769813001491 | 1960 | 49.763231666902 |
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