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
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	2.8488191423244253
1993	7.30063687449826
1994	8.289064729867482
1995	8.705352366255143
1996	7.571352232814851
1997	7.538237974683544
1998	8.581108186364833
1999	6.901242526644139
2000	6.364286049788633
2001	9.681504613200852
2002	16.05254290548707
2003	26.874063317634743
2004	30.561418475517417
2005	34.573151761517614
2006	37.01529190207157
2007	38.480036563071295
2008	39.25656168662155
2009	39.26702549575071
2010	38.961334590898375
2011	37.27611570247934
2012	41.42056534676127
2013	46.338456284153004
2014	47.3757264957265
2015	47.05849010989011
2016	43.001453639514736