Year | Value | 2022 | 37.033591082205 | 2021 | 32.939199923353 | 2020 | 29.224608731534 | 2019 | 30.902713507647 | 2018 | 31.680522797274 | 2017 | 30.878363432888 | 2016 | 29.922768322559 | 2015 | 30.123356488241 | 2014 | 30.668909461555 | 2013 | 31.12176664046 | 2012 | 31.985369769024 | 2011 | 33.220073049975 | 2010 | 32.727422989199 | 2009 | 29.056376798112 | 2008 | 28.452412614187 | 2007 | 25.179123444795 | 2006 | 25.777143586168 | 2005 | 24.338486631846 | 2004 | 20.764289949094 | 2003 | 20.684050355952 | 2002 | 23.01740778234 | 2001 | 27.199793928041 | 2000 | 26.286899208031 | 1999 | 13.201804408334 | 1998 | 22.422492329422 | 1997 | 29.030941232457 | 1996 | 27.808079925944 | 1995 | 28.138461864681 | 1994 | 29.871695323397 | 1993 | 28.998147454634 | 1992 | 23.300421656544 | 1991 | 22.073000513431 | 1990 | 22.453641772307 | 1989 | 26.186218212552 | 1988 | 23.316008880456 | 1987 | 24.102240516975 | 1986 | 21.02676270361 | 1985 | 23.527072237566 | 1984 | 23.056088774137 | 1983 | 23.915236915639 | 1982 | 15.531320582571 | 1981 | 20.197567887353 |
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