Year | Value | 2022 | 1.4660338438573 | 2021 | 1.3694253265962 | 2020 | 1.3678936018154 | 2019 | 1.2327049175721 | 2018 | 1.254333771646 | 2017 | 1.2300291098778 | 2016 | 1.1371359092622 | 2015 | 1.2702320395662 | 2014 | 1.2539124236884 | 2013 | 1.272360403928 | 2012 | 1.4236304000372 | 2011 | 1.3318765552101 | 2010 | 1.3873781239833 | 2009 | 1.3583538369604 | 2008 | 1.3676204845067 | 2007 | 1.3631063122769 | 2006 | 1.3700074614748 | 2005 | 1.3871777535512 | 2004 | 1.4302211796793 | 2003 | 1.4225443930068 | 2002 | 1.4559737016244 | 2001 | 1.6295840329361 | 2000 | 1.7255179883946 | 1999 | 1.7552345890065 | 1998 | 1.7573199488612 | 1997 | 1.7228156794418 | 1996 | 1.8144390161547 | 1995 | 1.9170223946512 | 1994 | 2.0013374021886 | 1993 | 2.0118717370405 | 1992 | 2.0428036760103 | 1991 | 2.129192231128 | 1990 | 2.2933052089802 | 1989 | 2.3596751422501 | 1988 | 2.4893752172298 | 1987 | 2.6147006889558 | 1986 | 2.6250366796807 | 1985 | 2.954721708185 | 1984 | 2.966005504413 | 1983 | 2.9362728999186 | 1982 | 2.660306745793 | 1981 | 2.5821087448348 | 1980 | 2.489895784886 | 1979 | 2.4970649013133 | 1978 | 2.3579573006207 | 1977 | 2.3142326628949 | 1976 | 2.3210469321354 | 1975 | 2.0042622333786 | 1974 | 2.2075639374068 | 1973 | 2.1107417254756 | 1972 | 2.3177820980076 | 1971 | 2.1079717457114 | 1970 | 2.2866162255175 | 1969 | 2.4341675343794 | 1968 | 2.2976725193957 | 1967 | 1.85195694358 | 1966 | 2.0796193601582 | 1965 | 1.884866824631 | 1964 | 1.930558573471 | 1963 | 1.9696329195804 | 1962 | 2.267745891926 | 1961 | 2.0312448260211 | 1960 | 2.2507470220485 |
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