Year | Value | 2022 | 50.193781468083 | 2021 | 50.195928459918 | 2020 | 50.19636579834 | 2019 | 50.194637941433 | 2018 | 50.19093565134 | 2017 | 50.184231828907 | 2016 | 50.173406562305 | 2015 | 50.162549891183 | 2014 | 50.153404444115 | 2013 | 50.141766904249 | 2012 | 50.127370597635 | 2011 | 50.110280059719 | 2010 | 50.090716667982 | 2009 | 50.068075094501 | 2008 | 50.044527881914 | 2007 | 50.020605757992 | 2006 | 49.995041297119 | 2005 | 49.965337372909 | 2004 | 49.932464784169 | 2003 | 49.896676578553 | 2002 | 49.857626446689 | 2001 | 49.818944198743 | 2000 | 49.782344087524 | 1999 | 49.744490307996 | 1998 | 49.703383592021 | 1997 | 49.66123437331 | 1996 | 49.617341854656 | 1995 | 49.566560833903 | 1994 | 49.51296815197 | 1993 | 49.470401409368 | 1992 | 49.432025697271 | 1991 | 49.387398575539 | 1990 | 49.371030272681 | 1989 | 49.36752054758 | 1988 | 49.339380832305 | 1987 | 49.351934368286 | 1986 | 49.375205151851 | 1985 | 49.364601345924 | 1984 | 49.372428644243 | 1983 | 49.387663291675 | 1982 | 49.375274182816 | 1981 | 49.359195777036 | 1980 | 49.372786810126 | 1979 | 49.383593969669 | 1978 | 49.381531705614 | 1977 | 49.382253510693 | 1976 | 49.384429832832 | 1975 | 49.378371297541 | 1974 | 49.364051373821 | 1973 | 49.351338711264 | 1972 | 49.348250535574 | 1971 | 49.353165529024 | 1970 | 49.359027145706 | 1969 | 49.366229856206 | 1968 | 49.373222523726 | 1967 | 49.38289793579 | 1966 | 49.396233343455 | 1965 | 49.400540352926 | 1964 | 49.394745982717 | 1963 | 49.388343006377 | 1962 | 49.380162007876 | 1961 | 49.372744446679 | 1960 | 49.368835614629 |
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