Year	% of total
1960	4.166666666666666
1961	3.697749196141479
1962	3.4226190476190474
1963	4.049295774647887
1964	4.181818181818182
1965	3.87858347386172
1966	4.022988505747127
1967	4.787961696306429
1968	4.773269689737471
1969	5.19774011299435
1970	4.995102840352595
1971	5.560235888795282
1972	4.938271604938272
1973	6.93000693000693
1974	9.873417721518987
1975	12.051077414205905
1976	13.555555555555557
1977	12.243589743589743
1978	10.446075663466967
1979	9.32817786370227
1980	14.964539007092197
1981	10.989010989010989
1982	11.841445057701957
1983	12.782316194137433
1984	13.355201499531397
1985	12.331316891577478
1986	13.06326809285389
1987	6.05911330049261
1988	4.854854854854855
1989	4.979591836734695
1990	7.697669421487603
1991	6.691605839416058
1992	8.840089285714285
1993	7.617439613526571
1994	4.626588785046729
1995	2.6327179487179486
1996	2.233705583756345
1997	2.4777027027027025
1998	1.8335000000000001
1999	0.9877441077441077
2000	0.6940694006309147
2001	0.455527950310559
2002	0.6845066666666667
2003	0.6245498783454988
2004	0.7693006993006993
2005	0.5405896805896805
2006	0.5432592592592592
2007	0.7820616113744076
2008	0.3517505995203837
2009	0.4244212962962963
2010	0.5604585152838428
2011	0.5820634920634921
2012	0.6405240174672489
2013	0.6889979123173278
2014	1.1239846743295019
2015	1.2295660749506903
2016	3.272778904665315