Year	% of total
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	2.666666666666667
1970	7.6923076923076925
1971	3.669724770642202
1972	3.2786885245901636
1973	3.125
1974	3.0303030303030303
1975	2.8776978417266186
1976	2.836879432624113
1977	2.631578947368421
1978	2.5157232704402515
1979	3.0303030303030307
1980	2.325581395348837
1981	2.209944751381215
1982	2.074688796680498
1983	1.9531250000000004
1984	2.100840336134454
1985	2.7932960893854752
1986	3.9215686274509802
1987	0.4464285714285714
1988	0.4540295119182747
1989	0.5148005148005148
1990	1.7461904761904763
1991	1.705581395348837
1992	1.6480898876404495
1993	1.6118681318681316
1994	1.5439999999999998
1995	1.1000999999999999
1996	0.6918867924528301
1997	0.34923809523809524
1998	0.3704040404040404
1999	0
2000	0
2001	0
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0
2009	0
2010	0
2011	0
2012	0
2013	0
2014	0
2015	0
2016	0
