Year	Percent
1960	7.12125
1961	0.57619
1962	1.03053
1963	3.26625
1964	0.78979
1965	1.16
1966	1.56634
1967	1.85333
1968	11.11969
1969	6.49206
1970	17.80089
1971	1.85749
1972	5.92249
1973	1.16682
1974	0.78627
1975	0.72838
1976	0.87679
1977	1.56337
1978	0.46629
1979	0.40196
1980	0.48956
1981	0.40832
1982	0.3478
1983	0.76315
1984	0.981
1985	1.43376
1986	4.23121
1987	1.53343
1988	2.82678
1989	3.02568
1990	4.04748
1991	2.46671
1992	3.31552
1993	4.85654
1994	2.70452
1995	2.31828
1996	1.1706
1997	0.92279
1998	0.62527
1999	0.70858
2000	0.65312
2001	0.54836
2002	0.91131
2003	0.94284
2004	1.02393
2005	0.59681
2006	0.64059
2007	0.79711
2008	0.45498
2009	0.79032
2010	0.5639
2011	0.17341
2012	0.13969
2013	0.2648
2014	0.70228
2015	0.20394
2016	0.17943
2017	0.39402