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	0.10591817820733483
1975	1.3470093919920907
1976	2.2764227642276422
1977	3.0213619733270387
1978	11.150927487352446
1979	4.733347611908331
1980	8.393562686710995
1981	18.130569194398984
1982	18.98168825368468
1983	15.763739487580677
1984	19.169763436961844
1985	19.247050346753127
1986	27.527652282286958
1987	13.944689667597512
1988	22.684505826499784
1989	23.696717659290066
1990	15.496842465753428
1991	16.236496698459284
1992	24.350325123152707
1993	26.423465501092725
1994	26.715625185625186
1995	23.9518247734139
1996	20.074267254038176
1997	25.078142976822114
1998	26.283586464162
1999	27.67248412496825
2000	27.857579225352108
2001	40.571063829787235
2002	28.51047287496373
2003	32.02697737068966
2004	24.717498665242925
2005	25.639760791861427
2006	24.665875267665953
2007	29.336000000000002
2008	44.41551119503642
2009	42.61357543391188
2010	34.36607978977544
2011	29.310433266932268
2012	31.841298900536945
2013	33.87728343365611
2014	34.572108150470214
2015	36.1954917184265
2016	33.41366534914361