| Year | Value | | 2022 | 85.915923085917 | | 2021 | 86.579960694248 | | 2020 | 89.179953530391 | | 2019 | 86.587771235612 | | 2018 | 84.536021934525 | | 2017 | 84.676077664446 | | 2016 | 86.367661613016 | | 2015 | 85.914976253449 | | 2014 | 77.644496549378 | | 2013 | 74.028221590634 | | 2012 | 72.943375927147 | | 2011 | 74.481439288688 | | 2010 | 76.129695509214 | | 2009 | 80.210563290408 | | 2008 | 75.501168767094 | | 2007 | 77.283943086612 | | 2006 | 77.129088790213 | | 2005 | 82.292033736567 | | 2004 | 84.165781904031 | | 2003 | 87.534295071647 | | 2002 | 89.786676812333 | | 2001 | 91.015089504959 | | 2000 | 90.90480638085 | | 1999 | 91.634605911431 | | 1998 | 89.277281457209 | | 1997 | 88.61648774728 | | 1996 | 88.455328940037 | | 1995 | 89.391140790626 | | 1994 | 91.163032325924 | | 1993 | 92.741819664494 | | 1992 | 92.314999369038 | | 1991 | 89.908506415358 | | 1990 | 88.617371599601 | | 1989 | 89.070695883485 | | 1988 | 90.390579566534 | | 1987 | 90.853663241056 | | 1986 | 90.824408575584 | | 1985 | 84.32861851945 | | 1984 | 82.493400596869 | | 1983 | 82.48403267572 | | 1982 | 84.715558635921 | | 1981 | 83.636675667079 | | 1980 | 81.120361124385 | | 1979 | 82.389978938033 | | 1978 | 82.818276109678 | | 1977 | 83.713476099782 | | 1976 | 83.028152267364 | | 1975 | 83.25574629037 | | 1974 | 76.923809070575 | | 1973 | 80.191516302627 | | 1972 | 82.769138755981 | | 1971 | 86.163183773817 | | 1970 | 83.388511835789 | | 1969 | 85.603042375951 | | 1968 | 86.244113029827 | | 1967 | 89.219289453168 | | 1966 | 88.981132075472 | | 1965 | 88.259052924791 | | 1964 | 87.559956676466 | | 1963 | 93.514644351464 | | 1962 | 94.0116388211 | | 1961 | 95.730706075534 | | 1960 | 92.654610404108 |
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