| Year | Value | | 2022 | 0.30140121683528 | | 2021 | 0.025272987891345 | | 2020 | 0.0022906802096937 | | 2019 | 0.032233064292521 | | 2018 | 0.054535454138139 | | 2017 | 0.090167266376756 | | 2016 | 0.068708232571569 | | 2015 | 0.13240433028797 | | 2014 | 0.18102209785462 | | 2013 | 0.24216562674113 | | 2012 | 0.27732102551461 | | 2011 | 0.16014042076572 | | 2010 | 0.23788669289018 | | 2009 | 0.26553767283277 | | 2008 | 0.36163084740164 | | 2007 | 0.45552640070274 | | 2006 | 0.46640352595509 | | 2005 | 0.59209965992996 | | 2004 | 0.62710398238553 | | 2003 | 0.72366176557857 | | 2002 | 0.69424013521097 | | 2001 | 0.79004758106815 | | 2000 | 0.9826761660643 | | 1999 | 1.2712485515712 | | 1998 | 1.0514216247321 | | 1997 | 1.2520976099419 | | 1996 | 1.0227645411617 | | 1995 | 0.85993346106168 | | 1994 | 1.4000644941944 | | 1993 | 1.1855406144071 | | 1992 | 1.3157431144969 | | 1991 | 1.0794636253025 | | 1990 | 0.7123134711322 | | 1989 | 0.7659148284138 | | 1988 | 0.6884005176576 | | 1987 | 0.74809910024983 | | 1986 | 0.76451598597193 | | 1985 | 0.81732139513889 | | 1984 | 1.0457354601341 | | 1983 | 0.91966798237099 | | 1982 | 1.2224281879171 | | 1981 | 1.4819683080138 | | 1980 | 1.6860123160757 | | 1979 | 1.7404191163689 | | 1978 | 1.3068430906221 | | 1977 | 1.6272708664891 | | 1976 | 1.6132619592804 | | 1975 | 1.5771704098109 | | 1974 | 1.5174192000468 | | 1973 | 1.4871505014096 | | 1972 | 1.5163926692462 | | 1971 | 1.5890031253898 | | 1970 | 1.6595789230044 | | 1969 | 1.7372976861109 | | 1968 | 1.8322860030699 | | 1967 | 1.9455380416704 | | 1966 | 2.0782539182528 | | 1965 | 2.231757996883 | | 1964 | 2.4079632860718 | | 1963 | 2.6089232743809 | | 1962 | 2.8373367949186 | | 1961 | 0.60024932699085 |
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