Year	% of total
1960	91.66666666666666
1961	91.11111111111111
1962	79.16666666666667
1963	75
1964	90.38461538461539
1965	89.83050847457626
1966	94.23076923076923
1967	96.73913043478262
1968	97.57009345794391
1969	96.67519181585678
1970	95.24647887323943
1971	79.89690721649484
1972	76.43908969210175
1973	43.54727398205659
1974	40.68594485541359
1975	42.21311475409836
1976	43.99486191393706
1977	51.21951219512195
1978	58.5838991270611
1979	50.1085776330076
1980	51.63073521282476
1981	49.470161740100394
1982	49.384787472035796
1983	48.30564784053156
1984	39.8776758409786
1985	34.184561810795124
1986	41.32841328413284
1987	37.01002734731084
1988	38.917089678511
1989	38.6277001270648
1990	20.510338983050847
1991	20.14742528735632
1992	22.51108459869848
1993	23.016276595744685
1994	15.939887387387389
1995	18.69295010845987
1996	21.52031779661017
1997	21.182049689440994
1998	24.768985801217042
1999	21.986784232365146
2000	22.300385438972164
2001	27.462467248908297
2002	27.35429561200924
2003	26.395717539863323
2004	27.399029345372462
2005	30.254730021598274
2006	35.762326732673266
2007	38.93358024691358
2008	38.80094430992736
2009	36.93192857142857
2010	40.975073375262056
2011	38.81558510638298
2012	39.626243567753
2013	45.22633333333333
2014	45.33745454545454
2015	44.56609489051095
2016	43.09206654991243