Year	% of total
1960	6.5817409766454364
1961	7.676348547717843
1962	5.1020408163265305
1963	5.084745762711865
1964	3.856382978723405
1965	5.357142857142857
1966	7.369758576874205
1967	11.63895486935867
1968	8.868501529051988
1969	8.365019011406845
1970	9.69637610186092
1971	6.005221932114883
1972	7.430340557275541
1973	5.694760820045557
1974	7.948369565217392
1975	5.684071381361534
1976	4.952978056426332
1977	3.852414541508411
1978	3.9647577092511015
1979	4.264214046822742
1980	2.4719969100038623
1981	3.1692766592095447
1982	1.9630484988452657
1983	2.2705157314304247
1984	2.2864401397268974
1985	2.119164619164619
1986	1.8541033434650456
1987	2.153558052434457
1988	2.471315092674316
1989	2.2443890274314215
1990	1.9201745454545456
1991	1.8818169209431346
1992	1.8359156785243742
1993	1.7535895883777237
1994	1.5857297297297297
1995	1.3987969483568075
1996	1.3542897727272727
1997	1.4321067106710672
1998	1.1047515856236787
1999	1.4971118951612903
2000	1.3315432393693265
2001	1.185635103926097
2002	0.9956419696272435
2003	0.2850434385002286
2004	0
2005	0
2006	0
2007	0
2008	0
2009	0
2010	0.2004555393586006
2011	0.17108864696734058
2012	0
2013	0
2014	0
2015	0
2016	0