| Year | Value | | 2022 | 132.41818969607 | | 2021 | 119.33664699664 | | 2020 | 115.71117886527 | | 2019 | 117.55552211969 | | 2018 | 116.41197634552 | | 2017 | 111.72247153567 | | 2016 | 109.80106621916 | | 2015 | 108.38692178976 | | 2014 | 107.60733875753 | | 2013 | 108.04689089273 | | 2012 | 107.39170940819 | | 2011 | 105.23541591478 | | 2010 | 100 | | 2009 | 99.228983584812 | | 2008 | 93.326148234124 | | 2007 | 83.651135798375 | | 2006 | 79.232299784447 | | 2005 | 76.405239595424 | | 2004 | 75.012435748632 | | 2003 | 64.491792405903 | | 2002 | 64.41717791411 | | 2001 | 59.617760700486 | | 2000 | 57.414046185313 | | 1999 | 56.864292244427 | | 1998 | 56.713932192219 | | 1997 | 55.482859264766 | | 1996 | 51.920187603004 | | 1995 | 49.272004720697 | | 1994 | 50.745412309449 | | 1993 | 45.275909533223 | | 1992 | 44.512479891417 | | 1991 | 40.825474939438 | | 1990 | 41.581932621045 | | 1989 | 36.083380010655 | | 1988 | 33.893022514758 | | 1987 | 31.235543685519 | | 1986 | 29.871363473186 | | 1985 | 28.251544720182 | | 1984 | 25.897346159652 | | 1983 | 23.151555834545 | | 1982 | 19.879382514438 | | 1981 | 16.804748066547 | | 1980 | 13.945082391649 | | 1979 | 10.481301294073 | | 1978 | 9.4324546850058 | | 1977 | 9.2421895316302 | | 1976 | 8.0639785400525 | | 1975 | 7.6870306315906 | | 1974 | 7.0660815954786 | | 1973 | 5.6534225383328 | | 1972 | 5.0583463787571 | | 1971 | 4.7051397970834 | | 1970 | 4.4910752021297 | | 1969 | 4.3711990289556 | | 1968 | 4.197806707043 | | 1967 | 4.1271653907083 | | 1966 | 4.1485718502037 | | 1965 | 4.0329769689286 | | 1964 | 3.9494917768967 | | 1963 | 3.7504117035897 | | 1962 | 3.7247239521953 | | 1961 | 3.6283948844661 |
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