Year	% of total
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0.05221188532371369
1979	0.0048520135856380394
1980	0.058080441411354725
1981	0.036727573225599115
1982	0.08430992327796982
1983	0.0162002349034061
1984	0.0765579543714592
1985	0.11683045838773967
1986	0.7247286189370648
1987	1.0613673573081917
1988	1.8260995790390477
1989	3.9324068224889452
1990	4.696351817267634
1991	5.555828813795022
1992	5.83225055062404
1993	6.239295765597893
1994	6.727478724095367
1995	7.876226078687745
1996	8.629165812887571
1997	9.86883103466088
1998	10.568753675522311
1999	12.576971535230985
2000	13.36147677961407
2001	15.485278592375368
2002	16.215357005573708
2003	18.519052746851617
2004	19.077869545859304
2005	22.211712267563083
2006	22.783742770692097
2007	24.11334532996505
2008	24.07809401114206
2009	23.010001389709206
2010	24.20106455304254
2011	26.519154916278488
2012	25.94931008270494
2013	27.033709023478014
2014	27.03206816580554
2015	25.65512841662163
2016	23.393656798099254