Year	% of total
1960	100
1961	100
1962	100
1963	100
1964	100
1965	100
1966	100
1967	100
1968	100
1969	97.33333333333333
1970	92.3076923076923
1971	96.33027522935781
1972	95.90163934426229
1973	96.87500000000001
1974	96.96969696969697
1975	97.12230215827337
1976	97.16312056737588
1977	96.71052631578947
1978	97.48427672955975
1979	96.96969696969698
1980	97.09302325581395
1981	92.81767955801105
1982	97.92531120331951
1983	98.04687500000001
1984	97.89915966386555
1985	97.20670391061452
1986	97.05882352941177
1987	98.32589285714285
1988	98.1838819523269
1989	97.94079794079794
1990	99.96940476190477
1991	99.35011627906975
1992	100.1214606741573
1993	100.3387912087912
1994	99.202
1995	100.4758
1996	99.63169811320755
1997	102.32676190476191
1998	107.78757575757577
1999	98.77774774774775
2000	99.53285714285714
2001	99.44406779661017
2002	98.46039370078739
2003	99.29107692307693
2004	98.3068085106383
2005	99.13544827586207
2006	97.45178082191781
2007	95.29936046511627
2008	98.60155555555555
2009	98.58517587939699
2010	94.77512077294686
2011	96.44712328767123
2012	97.1755
2013	93.00845454545454
2014	99.24182539682539
2015	83.53301694915255
2016	81.822384341637