Year	% of total
1971	33.78378378378378
1972	41.46341463414634
1973	39.57219251336899
1974	19.230769230769234
1975	25
1976	20.37037037037037
1977	18.181818181818183
1978	10.793650793650794
1979	16.619718309859156
1980	23.380281690140844
1981	16.574585635359114
1982	25.895316804407713
1983	9.433962264150944
1984	17.105263157894736
1985	29.336734693877553
1986	25.05694760820046
1987	28.74743326488706
1988	18.181818181818183
1989	25.127334465195243
1990	10.897435897435898
1991	8.868144690781797
1992	12.150537634408602
1993	10.51567239635996
1994	7.251908396946565
1995	11.578044596912521
1996	8.248232521602514
1997	6.647605432451751
1998	6.827048114434331
1999	1.8927444794952681
2000	5.399325084364454
2001	3.7153322867608587
2002	4.41025641025641
2003	5.667627281460135
2004	5.635103926096998
2005	5.061619718309859
2006	3.276595744680851
2007	3.4077079107505073
2008	4.22369964802503
2009	4.73418703919286
2010	3.756043138713276
2011	2.0505309410472354
2012	2.6456918126564175
2013	3.289473684210526
2014	3.0983997276132107
2015	4.070737404070737