Year | Value | 2022 | 2.3303719393135 | 2021 | 2.4064152104384 | 2020 | 2.4388213326666 | 2019 | 2.4145532198879 | 2018 | 2.4234507250405 | 2017 | 2.4644595282279 | 2016 | 2.4528610572273 | 2015 | 2.4253456736508 | 2014 | 2.4554817308977 | 2013 | 2.4587103119339 | 2012 | 2.4591343619903 | 2011 | 2.4458864434141 | 2010 | 2.406438777794 | 2009 | 2.3701239981312 | 2008 | 2.3308686690672 | 2007 | 2.3578542082972 | 2006 | 2.4491182674123 | 2005 | 2.4761219186445 | 2004 | 2.4964869334055 | 2003 | 2.6155522892755 | 2002 | 2.5987435707266 | 2001 | 2.428372252618 | 2000 | 2.4392778719015 | 1999 | 2.5003039024166 | 1998 | 2.4685405742063 | 1997 | 2.4739532809578 | 1996 | 2.5343311048098 | 1995 | 2.5837708376521 | 1994 | 2.6910977284513 | 1993 | 2.8384224595022 | 1992 | 2.6817878457113 | 1991 | 2.4459188238363 | 1990 | 2.4919630663901 | 1989 | 2.5156661738871 | 1988 | 2.5081903714691 | 1987 | 2.5734171991326 | 1986 | 2.6040451211642 | 1985 | 2.6847292462486 | 1984 | 2.7244597826589 | 1983 | 2.7165323084536 | 1982 | 2.5273158420637 | 1981 | 2.2298719796614 | 1980 | 2.3549999818429 | 1979 | 2.6480097722741 | 1978 | 2.5777918164504 | 1977 | 2.4033760265655 | 1976 | 2.3809140468393 | 1975 | 2.4812555407255 | 1974 | 2.5737356356645 | 1973 | 2.5504097414766 | 1972 | 2.2795134802535 | 1971 | 2.2311052045456 | 1970 | 2.5164099444274 | 1969 | 2.6146156349017 | 1968 | 2.6268569941102 | 1967 | 2.585703908807 | 1966 | 2.552541604665 | 1965 | 2.5560862710873 | 1964 | 2.5239607167245 | 1963 | 2.4896651334387 | 1962 | 2.4766181235179 | 1961 | 2.4293110647922 |
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