| Year | Value | | 2022 | 96.23638875028 | | 2021 | 94.39252922274 | | 2020 | 93.303620925937 | | 2019 | 94.624205573167 | | 2018 | 93.394165473117 | | 2017 | 92.695923774708 | | 2016 | 91.292398064859 | | 2015 | 90.928114730609 | | 2014 | 92.172325667051 | | 2013 | 91.552898748617 | | 2012 | 92.402060616081 | | 2011 | 90.765898316454 | | 2010 | 90.753005288662 | | 2009 | 90.967177495554 | | 2008 | 92.600904232328 | | 2007 | 90.001792119663 | | 2006 | 89.669610253886 | | 2005 | 89.108370456535 | | 2004 | 86.311626474591 | | 2003 | 85.00600855398 | | 2002 | 85.640660224889 | | 2001 | 86.327956088899 | | 2000 | 85.890022104497 | | 1999 | 86.048021715374 | | 1998 | 83.330943183142 | | 1997 | 86.769163105894 | | 1996 | 85.527265935374 | | 1995 | 84.167291022883 | | 1994 | 83.322134617255 | | 1993 | 85.393130291608 | | 1992 | 83.005898207424 | | 1991 | 82.600725063688 | | 1990 | 86.521766052179 | | 1989 | 87.366335604648 | | 1988 | 87.552358714755 | | 1987 | 86.143945891465 | | 1986 | 89.050632419364 | | 1985 | 93.712896345919 | | 1984 | 92.302561683841 | | 1983 | 91.536745273569 | | 1982 | 91.677232469251 | | 1981 | 90.731354872105 | | 1980 | 93.046771913792 | | 1979 | 93.661339558269 | | 1978 | 92.066759671986 | | 1977 | 90.202874161925 | | 1976 | 90.18363965512 | | 1975 | 92.628369444969 | | 1974 | 90.497378039091 | | 1973 | 86.65026966159 | | 1972 | 87.454502222304 | | 1971 | 87.220176802977 | | 1970 | 86.940587631673 | | 1969 | 88.555950567124 | | 1968 | 88.003969082933 | | 1967 | 87.68075170202 | | 1966 | 86.503008577647 | | 1965 | 87.207366743404 | | 1964 | 86.669894295167 | | 1963 | 89.230001813894 | | 1962 | 92.16077953715 | | 1961 | 93.672564115638 | | 1960 | 92.511482020836 |
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