Year	% of total
1960	34.54790823211876
1961	27.298444130127297
1962	31.806615776081422
1963	21.835883171070936
1964	20.769230769230766
1965	13.575268817204304
1966	9.007832898172323
1967	15.19756838905775
1968	7.509386733416772
1969	15.507411630558723
1970	12.629070691024625
1971	11.7816091954023
1972	7.784431137724551
1973	4.906333630686886
1974	9.333333333333332
1975	14.628297362110313
1976	8.907185628742514
1977	6.66194188518781
1978	8.677098150782363
1979	2.8037383177570097
1980	2.7869940278699405
1981	3.6410923276983103
1982	4.846103470857891
1983	4.190476190476191
1984	4.0736607142857135
1985	4.316939890710382
1986	2.75377969762419
1987	2.947678703021371
1988	2.9385574354407833
1989	4.190632703368941
1990	6.563842482100238
1991	7.031383495145631
1992	2.8207692307692307
1993	1.0673180873180874
1994	0.713929203539823
1995	0.9510951008645532
1996	0.6521340629274965
1997	0.7081103448275862
1998	0.695385587863464
1999	4.05641592920354
2000	14.171427083333334
2001	18.3996357226792
2002	14.65930011862396
2003	5.532548298068077
2004	6.943225499524262
2005	5.295306859205776
2006	9.338099902056808
2007	7.808060836501901
2008	8.082926525529265
2009	7.978007863695937
2010	14.880579710144929
2011	19.403473193473193
2012	14.462722646310432
2013	8.418719646799119
2014	6.800305164319248
2015	4.880331404523934
2016	5.528140703517588