| Year | Value | | 2022 | 0.37932088622502 | | 2021 | 0.90025678287942 | | 2020 | 1.4102600772194 | | 2019 | 1.4147318851685 | | 2018 | 1.4330432518704 | | 2017 | 1.4639788187309 | | 2016 | 1.3914541600331 | | 2015 | 0.72162400297426 | | 2014 | 0.097024253351022 | | 2013 | 0.053713460644788 | | 2012 | 0.012399512301732 | | 2011 | 0.049588827000709 | | 2010 | 0.039240389189906 | | 2009 | 0.037174721617715 | | 2008 | 0.10333568480404 | | 2007 | 0.099302819671085 | | 2006 | 0.045546769037161 | | 2005 | 0.62733899136707 | | 2004 | 1.2518379893143 | | 2003 | 1.2292495957113 | | 2002 | 1.2207592122052 | | 2001 | 1.2730708904574 | | 2000 | 1.005918478455 | | 1999 | 0.75054755670778 | | 1998 | 0.82811574411955 | | 1997 | 0.80557338828574 | | 1996 | 0.7573123307641 | | 1995 | 0.7414517228164 | | 1994 | -2.1631067432783 | | 1993 | -1.9956535455051 | | 1992 | -1.7346769077655 | | 1991 | -1.4190652708113 | | 1990 | 0.023165454093846 | | 1989 | 1.1244281986835 | | 1988 | 1.0317314003432 | | 1987 | 1.0077068234011 | | 1986 | 0.95211777720257 | | 1985 | 0.97013218146087 | | 1984 | 1.0378250025745 | | 1983 | 1.1369771147482 | | 1982 | 1.2554706526678 | | 1981 | 1.2900129277957 | | 1980 | 1.2809899335756 | | 1979 | 1.2809304901708 | | 1978 | 1.16004464602 | | 1977 | 1.0347217779603 | | 1976 | 1.0480017563424 | | 1975 | 1.0814929391407 | | 1974 | 1.1084119234064 | | 1973 | 1.1182912239745 | | 1972 | 1.1335117846196 | | 1971 | 1.1517137541254 | | 1970 | 1.0598447957724 | | 1969 | 1.0073986915827 | | 1968 | 1.0579282255641 | | 1967 | 1.1045360001011 | | 1966 | 1.3092805689625 | | 1965 | 1.3991667155873 | | 1964 | 1.2804487975448 | | 1963 | 1.1997642065103 | | 1962 | 1.1246253572253 | | 1961 | 1.2164396425344 |
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