Year	% of total
1960	97.59036144578313
1961	97.97979797979798
1962	98.13084112149532
1963	98.21428571428571
1964	97.45762711864407
1965	97.33333333333333
1966	97.14285714285714
1967	98.49624060150376
1968	98.13664596273293
1969	96.47887323943661
1970	94.08866995073892
1971	95.37572254335261
1972	94.87179487179486
1973	95.78059071729959
1974	94.61538461538463
1975	91.70305676855895
1976	92.5531914893617
1977	91.45569620253164
1978	94.22110552763819
1979	94.21487603305785
1980	94.1031941031941
1981	94.45910290237468
1982	95.97855227882039
1983	94.55958549222797
1984	96.32352941176472
1985	98.58156028368793
1986	94.7136563876652
1987	93.02325581395348
1988	92.54237288135593
1989	92.81045751633987
1990	96.36946859903381
1991	97.4841089108911
1992	95.60923076923076
1993	95.96617021276596
1994	94.09038922155689
1995	96.5255291005291
1996	92.66075268817204
1997	93.86092457420925
1998	96.95651053864168
1999	96.95651053864168
2000	95.63369318181817
2001	96.6386187845304
2002	97.20460317460316
2003	96.70083756345177
2004	97.07851385390428
2005	96.13486486486485
2006	96.2228459530026
2007	97.10587341772151
2008	96.93863636363635
2009	97.50695652173913
2010	94.73083333333334
2011	95.67919540229884
2012	94.1527027027027
2013	93.47390566037737
2014	92.42403197158082
2015	89.40111459968603
2016	95.13685314685314