| Year | Value | | 2022 | 1.2651434745417 | | 2021 | 0.99832266041726 | | 2020 | 0.97340596038654 | | 2019 | 0.94030525392504 | | 2018 | 0.93821602730621 | | 2017 | 0.94000927013575 | | 2016 | 1.0626383218523 | | 2015 | 1.0514980960322 | | 2014 | 1.0325291647879 | | 2013 | 1.0812367729392 | | 2012 | 1.1820274321119 | | 2011 | 1.0587849696334 | | 2010 | 0.81673892592271 | | 2009 | 0.65174977098315 | | 2008 | 0.49795223603132 | | 2007 | 0.31107518260845 | | 2006 | 0.47617399902736 | | 2005 | 0.85644209588343 | | 2004 | 0.6343516688771 | | 1994 | 29.727685325265 | | 1993 | 18.983790523691 | | 1992 | 10.13422818792 | | 1991 | 7.183908045977 | | 1988 | 2.4077819512665 | | 1987 | 2.2872121710526 | | 1986 | 2.8953626634958 | | 1985 | 2.9543051803125 | | 1984 | 2.940483205657 | | 1983 | 4.7060966723342 | | 1982 | 5.0179418914226 | | 1981 | 3.1128174837567 | | 1980 | 1.4917514917515 | | 1979 | 1.1546493059821 | | 1978 | 1.2409369771333 | | 1977 | 1.1515601783061 | | 1976 | 1.0725657784481 | | 1975 | 0.95238095238095 | | 1974 | 0.93429158110883 | | 1973 | 0.96899224806202 | | 1972 | 1.1002444987775 | | 1971 | 1.1859443631039 | | 1970 | 1.0987310430207 | | 1969 | 0.99348534201954 | | 1968 | 1.1018786127168 | | 1967 | 1.1685823754789 | | 1966 | 1.1451942740286 | | 1965 | 1.1774967291758 |
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