Year	% of total
1960	76.58496610295761
1961	77.66851824050444
1962	80.09573480031435
1963	81.11258278145695
1964	82.5121359223301
1965	84.43117278529188
1966	86.9923216811477
1967	86.24647924748898
1968	88.96388954448902
1969	90.22900763358778
1970	90.23102572245158
1971	90.19854343679556
1972	91.31920415224914
1973	90.94648478488982
1974	90.68667951895712
1975	89.29721881947282
1976	90.92683331949173
1977	92.20906876362237
1978	91.39194983632257
1979	90.49222797927462
1980	89.36583371659256
1981	90.46160346466672
1982	87.343262494849
1983	84.60812680840357
1984	80.92101055324592
1985	79.21245959447548
1986	78.69724553729756
1987	78.45256370893459
1988	77.54229173316311
1989	76.65081880612784
1990	71.93093720712277
1991	71.21038163716814
1992	67.89927048458149
1993	68.18764112546452
1994	69.75387587621816
1995	70.7391567920316
1996	64.85952238805972
1997	68.37440397350993
1998	69.13011309115834
1999	67.92305919329492
2000	69.35502815315314
2001	70.98613523809524
2002	79.98567382450943
2003	74.90113224637682
2004	74.51694345960067
2005	76.43661023700457
2006	73.46748261758692
2007	72.98216801018243
2008	79.06894257854822
2009	75.58056436567165
2010	79.47325368792852
2011	86.46521193092622
2012	83.91035587188611
2013	81.2798914919852
2014	82.89670843989771
2015	69.08366071428571
2016	82.8218277906677