Year | Value | 2022 | 2.0216871021007 | 2021 | 2.0979881027902 | 2020 | 2.1956370431171 | 2019 | 2.289855365319 | 2018 | 2.3913552246359 | 2017 | 2.5559185978816 | 2016 | 2.8042121092134 | 2015 | 3.0869163835556 | 2014 | 3.341104101376 | 2013 | 3.5051573934423 | 2012 | 3.5582225998144 | 2011 | 3.525161877573 | 2010 | 3.4219706866041 | 2009 | 3.2929774631171 | 2008 | 3.1880765302455 | 2007 | 3.0956097725807 | 2006 | 2.9845299358119 | 2005 | 2.8688130276013 | 2004 | 2.7697631215912 | 2003 | 2.6987469955443 | 2002 | 2.6513795373936 | 2001 | 2.6095432158919 | 2000 | 2.5597938864961 | 1999 | 2.5245811925774 | 1998 | 2.5131488812229 | 1997 | 2.506560362319 | 1996 | 2.5203693534191 | 1995 | 2.5595656124927 | 1994 | 2.6144135588665 | 1993 | 2.6579005735272 | 1992 | 2.6816543229526 | 1991 | 2.706305535456 | 1990 | 2.7347405832644 | 1989 | 2.7606811683874 | 1988 | 2.7730763355268 | 1987 | 2.764442661225 | 1986 | 2.7474894707886 | 1985 | 2.7299184633079 | 1984 | 2.7145231862383 | 1983 | 2.6881394307716 | 1982 | 2.6541366716776 | 1981 | 2.6123007314617 | 1980 | 2.5541081714188 | 1979 | 2.5034535052298 | 1978 | 2.4454940119853 | 1977 | 2.3692294289265 | 1976 | 2.2832586520163 | 1975 | 2.1975154669721 | 1974 | 2.123408520136 | 1973 | 2.067382432304 | 1972 | 2.0449063265455 | 1971 | 2.0716882063583 | 1970 | 2.1262922200591 | 1969 | 1.9024281298982 | 1968 | 1.6124463733974 | 1967 | 1.5512048397086 | 1966 | 1.4888567509334 | 1965 | 1.4172111409137 | 1964 | 1.3498622565296 | 1963 | 1.2922229880963 | 1962 | 1.2295829035696 | 1961 | 1.1599200028742 |
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