| Year | Value | | 2022 | -6.1872529820496 | | 2021 | 0.81484647152895 | | 2020 | 0.60024151846542 | | 2019 | 0.70390564111746 | | 2018 | 0.72208040522285 | | 2017 | 0.73044317529829 | | 2016 | 0.70138209784133 | | 2015 | 0.63806946816072 | | 2014 | 0.5683892640529 | | 2013 | 0.55964721741086 | | 2012 | 0.57922059636439 | | 2011 | 0.64122892051507 | | 2010 | 0.65827544663591 | | 2009 | 0.64428136254705 | | 2008 | 0.70192274454598 | | 2007 | 0.73528228399131 | | 2006 | 0.75950591553106 | | 2005 | 0.75297744549364 | | 2004 | 0.7547969512736 | | 2003 | 0.79211363763553 | | 2002 | -2.1706987803 | | 2001 | -1.9906322043828 | | 2000 | 0.49389641663332 | | 1999 | 0.56064822477944 | | 1998 | 0.66730270106626 | | 1997 | 0.60879735453791 | | 1996 | 0.51572987963683 | | 1995 | 0.44539850047226 | | 1994 | 0.33958607948504 | | 1993 | 0.79766585151642 | | 1992 | -1.0738531907604 | | 1991 | 0.99042598009936 | | 1990 | -1.8037504790681 | | 1989 | -1.1700385987501 | | 1988 | 0.11237242382403 | | 1987 | 0.14710929264027 | | 1986 | 0.026519754526249 | | 1985 | 0.0014731135024134 | | 1984 | 0.23397230973017 | | 1983 | 0.24954660082538 | | 1982 | 0.29581278329628 | | 1981 | 0.33326882518889 | | 1980 | 0.40248874474625 | | 1979 | 0.13501157268094 | | 1978 | 0.11180475463559 | | 1977 | 0.51909888035064 | | 1976 | 0.4331634607133 | | 1975 | 0.48273930785632 | | 1974 | 0.66796736070825 | | 1973 | 0.52063344062239 | | 1972 | 0.4652137421538 | | 1971 | 0.54999651445838 | | 1970 | 0.65472736247273 | | 1969 | 0.76850966869777 | | 1968 | 0.71196474274479 | | 1967 | 0.62974748090139 | | 1966 | 0.6547012021586 | | 1965 | 0.73191103529221 | | 1964 | 0.81609404955012 | | 1963 | 0.81037832435622 | | 1962 | 0.87525903356163 | | 1961 | 0.95815588130066 |
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