Year	% of total
1960	0.6795324816526229
1961	0.7093995439574361
1962	0.6139004604253453
1963	0.5915909571096556
1964	0.5858966310943712
1965	0.6398348813209495
1966	0.6048780487804878
1967	0.6473724295506473
1968	0.6046993780234968
1969	0.6340432450008129
1970	9.6045197740113
1971	9.202869129787523
1972	9.066077003121748
1973	8.195199575653096
1974	8.70302345295281
1975	9.815168897386869
1976	6.6331964095542375
1977	6.521739130434782
1978	3.978906999041227
1979	5.707964601769912
1980	5.6748911465892595
1981	6.690561529271206
1982	8.23550337958022
1983	8.65739926095372
1984	8.1598942847704
1985	8.59481582537517
1986	7.5820009889566515
1987	7.294193757075853
1988	8.184665667983113
1989	10.054347826086957
1990	8.597734297928312
1991	7.44316644113667
1992	8.302861225785964
1993	7.583764705882354
1994	7.441791972866025
1995	6.845066666666666
1996	6.092246935996369
1997	8.964422468354432
1998	12.539556506516242
1999	16.81077738515901
2000	23.943699317543153
2001	28.258957593482346
2002	27.76044773054015
2003	29.550538970146267
2004	29.34672026310981
2005	27.943435032304382
2006	25.145142857142854
2007	13.548755020080321
2008	7.0761010989011
2009	9.766325531589414
2010	14.679571141709696
2011	13.67632274094416
2012	12.506763918970568
2013	11.212336628888355
2014	10.86802984683859
2015	11.125813102354519
2016	11.55939182915506