Annual % of total
1960 0.5035246727089627
1961 0.48543689320388345
1962 0.5952380952380952
1963 0.5555555555555555
1964 0.4975124378109453
1965 0.5163511187607572
1966 0.4694835680751174
1967 0.4062288422477996
1968 0.3908794788273615
1969 1.3845185651353054
1970 1.256913021618904
1971 1.206973625391149
1972 1.3211845102505697
1973 1.4073792316470142
1974 1.0865986170563053
1975 1.3201320132013201
1976 1.4290250873293109
1977 1.0392609699769053
1978 1.233875490745934
1979 0.896139705882353
1980 0.8049678012879485
1981 1.1563367252543941
1982 0.8813413585554603
1983 0.906655676900886
1984 0.9057225195553726
1985 0.9236453201970443
1986 0.9322198485142745
1987 0.7109004739336493
1988 0.761904761904762
1989 0.512
1990 0.506258628624022
1991 0.3127505330490405
1992 0.18872129849564528
1993 0.1834911470361817
1994 0.15643085673658016
1995 0.08790753424657534
1996 0.11423676012461059
1997 0.2176261127596439
1998 0.21257971014492752
1999 0.236217791411043
2000 0.2643676779813758
2001 0.22844257854821234
2002 0.2203841128821531
2003 0.21113321120125625
2004 0.23478539245909416
2005 1.9534254888739042
2006 2.373745399437108
2007 2.6044688874921436
2008 2.2215384615384615
2009 2.394360902255639
2010 2.4328214685054044
2011 2.836388648555113
2012 3.9870623441396504
2013 3.9359460817146683
2014 3.6753940483976457
2015 3.681517022961204
2016 3.7495481927710843