| Year | Value | | 2022 | 144.39864427569 | | 2021 | 136.84723682375 | | 2020 | 137.00539296463 | | 2019 | 133.06203318559 | | 2018 | 130.92165341248 | | 2017 | 126.54145284766 | | 2016 | 125.92606882162 | | 2015 | 125.28400629733 | | 2014 | 126.00788288288 | | 2013 | 119.81819204904 | | 2012 | 113.68881436888 | | 2011 | 107.34270706018 | | 2010 | 100 | | 2009 | 98.959459459459 | | 2008 | 92.405405405405 | | 2007 | 78.763513513514 | | 2006 | 73.155405405405 | | 2005 | 65.77541264352 | | 2004 | 61.282964765045 | | 2003 | 57.281378174954 | | 2002 | 52.906310169788 | | 2001 | 47.693576705096 | | 2000 | 44.604351857546 | | 1999 | 41.342601716509 | | 1998 | 38.272968636905 | | 1997 | 34.05083415728 | | 1996 | 31.504046603053 | | 1995 | 28.185397457671 | | 1994 | 25.709749220602 | | 1993 | 22.700556104853 | | 1992 | 20.794022405041 | | 1991 | 18.775444280706 | | 1990 | 16.319359355855 | | 1989 | 15.008019731606 | | 1988 | 13.058145132989 | | 1987 | 11.185901840128 | | 1986 | 10.078082125562 | | 1985 | 8.8737478146519 | | 1984 | 8.0988335193624 | | 1983 | 7.2931464542237 | | 1982 | 6.8651252008688 | | 1981 | 6.0762232829206 | | 1980 | 5.2201807762108 | | 1979 | 4.6159154773568 | | 1978 | 4.2718199599538 | | 1977 | 4.020042752098 | | 1976 | 3.7011249554806 | | 1975 | 3.5500586307671 | | 1974 | 3.2252898601227 | | 1973 | 2.7136758983908 | | 1972 | 2.6287998494458 | | 1971 | 2.4596371685447 |
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