| Year | Value | | 2022 | 99.344607694813 | | 2021 | 99.237126352977 | | 2020 | 96.52297683159 | | 2019 | 96.366143242761 | | 2018 | 96.999512736504 | | 2017 | 96.836817509073 | | 2016 | 96.169282590054 | | 2015 | 96.250048254385 | | 2014 | 96.730839418277 | | 2013 | 97.302196719955 | | 2012 | 97.297612475312 | | 2011 | 97.416781796303 | | 2010 | 96.60231018507 | | 2009 | 96.941099488891 | | 2008 | 95.564867480607 | | 2007 | 95.344836080066 | | 2006 | 96.08386762299 | | 2005 | 96.981246051609 | | 2004 | 96.814340651755 | | 2003 | 97.471764079446 | | 2002 | 96.021262157683 | | 2001 | 98.24809042128 | | 2000 | 99.013396035551 | | 1999 | 99.593084307143 | | 1998 | 99.962790292127 | | 1997 | 100.57677422281 | | 1996 | 101.41144821916 | | 1995 | 101.29137995711 | | 1994 | 101.22160920089 | | 1993 | 100.57028181886 | | 1992 | 100.77756128607 | | 1991 | 100.44376417461 | | 1990 | 100.54486521632 | | 1989 | 100.60387916878 | | 1988 | 100.39039013614 | | 1987 | 99.593885189997 | | 1986 | 99.41519444397 | | 1985 | 100.71666762165 | | 1984 | 99.938859463254 | | 1983 | 100.25763176699 | | 1982 | 100.57638993873 | | 1981 | 102.34944064233 | | 1980 | 102.76891048153 | | 1979 | 102.63606123585 | | 1978 | 100.31123141713 | | 1977 | 104.69999238107 | | 1976 | 102.81019376159 | | 1975 | 100.57613229435 | | 1974 | 101.75552698581 | | 1973 | 101.00957058004 | | 1972 | 100.77757688817 | | 1971 | 100.59456745875 | | 1970 | 100.32504921112 |
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