Year	% of total
1960	0.819672131147541
1961	2.74869109947644
1962	5.684931506849315
1963	12.398523985239853
1964	12.987886944818305
1965	11.215580926796507
1966	13.581129378127233
1967	17.70981507823613
1968	16.936050597329587
1969	16.944444444444446
1970	18.054532056005897
1971	32.3330832708177
1972	33.99122807017544
1973	27.618364418938306
1974	26.167471819645733
1975	23.719165085388994
1976	19.708029197080293
1977	16.109154929577464
1978	17.120280948200175
1979	14.389799635701275
1980	10.893246187363834
1981	10.302197802197801
1982	18.81918819188192
1983	11.27659574468085
1984	6.133828996282528
1985	3.4682080924855487
1986	11.564625850340136
1987	2.422145328719723
1988	9.253246753246753
1989	3.0063291139240507
1990	1.4423076923076923
1991	3.7089871611982885
1992	8.484848484848486
1993	5.663189269746647
1994	2.5996533795493932
1995	1.0266940451745379
1996	3.8636363636363633
1997	3.201970443349754
1998	0
1999	0
2000	0
2001	0
2002	0
2003	0.035855145213338116
2004	0.029568302779420463
2005	0.02986857825567503
2006	0.028336639274582034
2007	0.031240237425804434
2008	0.036683785766691124
2009	0.031725888324873094
2010	0.030959752321981428
2011	0.03773584905660377
2012	0.03627130939426913
2013	0
2014	0
2015	0