Year	% of total
1960	0
1961	0
1962	0
1963	1.0966415352981493
1964	1.411290322580645
1965	1.5897755610972568
1966	2.6136363636363633
1967	2.713510425592688
1968	4.25649530127142
1969	0.9990917347865576
1970	0.9874021109976168
1971	1.09053731682381
1972	1.2658227848101264
1973	1.1760355029585798
1974	1.2480131865544242
1975	1.6324951644100578
1976	2.1969998672507636
1977	13.995649021029733
1978	10.311313591495825
1979	3.589315525876461
1980	3.733993328311633
1981	14.927447601045202
1982	15.008384572386808
1983	7.367068469681209
1984	5.66176857850108
1985	7.696747114375654
1986	8.620603641805937
1987	11.308162886980163
1988	10.236873477427046
1989	18.731639882495248
1990	11.030725128960944
1991	12.077759692999868
1992	11.111349537037036
1993	12.424617936263477
1994	12.763691791878804
1995	12.353751532989943
1996	11.710172057811425
1997	12.777875269332057
1998	14.40197025052192
1999	15.559946423787837
2000	17.339554357828316
2001	13.64304873752202
2002	13.818853791661828
2003	22.680982183130354
2004	23.157169130091393
2005	20.976104225924423
2006	23.465618221258133
2007	24.688068345722844
2008	22.58372009177319
2009	24.336353717672417
2010	22.27764135346633
2011	27.453110980507393
2012	28.700794596742153
2013	25.879640534682082
2014	28.143120481927713
2015	30.02769486823856
2016	29.38808614646744