Year | Value | 2021 | 26.220896912935 | 2020 | 24.800502592801 | 2019 | 25.088935553227 | 2018 | 25.530919424022 | 2017 | 25.582261935517 | 2016 | 25.439975497641 | 2015 | 25.049166401854 | 2014 | 24.865209066885 | 2013 | 25.12011883049 | 2012 | 25.08719361154 | 2011 | 25.824226056935 | 2010 | 25.273273557042 | 2009 | 24.172876842876 | 2008 | 26.457894076305 | 2007 | 25.994715910599 | 2006 | 25.770394514272 | 2005 | 25.488132609925 | 2004 | 25.152328265427 | 2003 | 24.555404209057 | 2002 | 24.961580072501 | 2001 | 25.741470245652 | 2000 | 26.089164498452 | 1999 | 25.481668788246 | 1998 | 25.025112643853 | 1997 | 23.737131649194 | 1996 | 23.065012588009 | 1995 | 23.231573819181 | 1994 | 23.797094992458 | 1993 | 22.981091766116 | 1992 | 24.28031599149 | 1991 | 24.847137041141 | 1990 | 24.151294599568 | 1989 | 22.762271584715 | 1988 | 22.990749915473 | 1987 | 23.158795082956 | 1986 | 24.500683627785 | 1985 | 25.133573420135 | 1984 | 24.777631101094 | 1983 | 24.648530499906 | 1982 | 25.866139328526 | 1981 | 24.639426203616 | 1980 | 23.876065932529 | 1979 | 21.903778709363 | 1978 | 22.154222067446 | 1977 | 23.325774453639 | 1976 | 23.800695249131 | 1975 | 24.26560755532 | 1974 | 23.746073506231 | 1973 | 21.071583072499 | 1972 | 23.018485320481 |
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