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
1979	0
1980	0
1981	0.10343400910219282
1982	0.21942948334330745
1983	0.7023538344722855
1984	0.6686167989970748
1985	0.34650034650034656
1986	0.3334921391138638
1987	0.2965264049703474
1988	0.2372666877570389
1989	0.0837696335078534
1990	0.03983704508419337
1991	0.020027307482250137
1992	0
1993	0
1994	0
1995	1.4029419525065965
1996	1.8351097453906937
1997	2.841148480318884
1998	4.233354134165366
1999	4.781631613903032
2000	6.093444643212085
2001	4.5903075822603725
2002	6.190967109233554
2003	7.3954115810388865
2004	10.38100520956666
2005	10.215328118209474
2006	11.717857142857143
2007	11.852156006832416
2008	11.828428838632886
2009	11.681393865775888
2010	12.087554871520343
2011	10.933083478727687
2012	12.20341345827392
2013	12.194690490138646
2014	11.636677147603228
2015	9.789768164435946
2016	9.10566534149283