Year | Value | 2022 | 49.829811940808 | 2021 | 49.823284928511 | 2020 | 49.816171499937 | 2019 | 49.807292940819 | 2018 | 49.797605875867 | 2017 | 49.786281666478 | 2016 | 49.779006761794 | 2015 | 49.765998197184 | 2014 | 49.74535525023 | 2013 | 49.730220570813 | 2012 | 49.716186698198 | 2011 | 49.702348285142 | 2010 | 49.687713914191 | 2009 | 49.673282344646 | 2008 | 49.658545523778 | 2007 | 49.641153176265 | 2006 | 49.622147978304 | 2005 | 49.603978870485 | 2004 | 49.586326881407 | 2003 | 49.56718499578 | 2002 | 49.548248873029 | 2001 | 49.532257521227 | 2000 | 49.517608287446 | 1999 | 49.506117816471 | 1998 | 49.50012894401 | 1997 | 49.49334304936 | 1996 | 49.501198305852 | 1995 | 49.524609189248 | 1994 | 49.544949681766 | 1993 | 49.565639372617 | 1992 | 49.5904400442 | 1991 | 49.599776523323 | 1990 | 49.592381794789 | 1989 | 49.584495072434 | 1988 | 49.581586307338 | 1987 | 49.579613306046 | 1986 | 49.569983060207 | 1985 | 49.600787834501 | 1984 | 49.667440457496 | 1983 | 49.727458052649 | 1982 | 49.777080395915 | 1981 | 49.811423423571 | 1980 | 49.802496109642 | 1979 | 49.773445033689 | 1978 | 49.770171510749 | 1977 | 49.765906302216 | 1976 | 49.756062001076 | 1975 | 49.74269128858 | 1974 | 49.723332603145 | 1973 | 49.703412520343 | 1972 | 49.686884665143 | 1971 | 49.672032632288 | 1970 | 49.665855863598 | 1969 | 49.66872217998 | 1968 | 49.671045180355 | 1967 | 49.674360597381 | 1966 | 49.677081065297 | 1965 | 49.679006313254 | 1964 | 49.682025167554 | 1963 | 49.68547682485 | 1962 | 49.688476907503 | 1961 | 49.693883252297 | 1960 | 49.700944805388 |
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