Year	% of total
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	8.185260704922808
1990	11.902144035184167
1991	11.251342642320086
1992	10.312075983717776
1993	11.321151018693552
1994	15.228526398739165
1995	13.265669515669515
1996	12.033674480026411
1997	12.308429118773946
1998	10.185322461082283
1999	10.365767546956645
2000	10.061016949152542
2001	10.186779705921314
2002	8.362026561731431
2003	9.331998999249437
2004	50.128248020519685
2005	54.87880671224363
2006	70.1978417266187
2007	82.40904545804169
2008	83.75487787252493
2009	90.98934977578476
2010	71.17141503688164
2011	27.02259848433126
2012	18.576765485659195
2013	25.134681109888202
2014	7.113062568605928
2015	48.44325234038077