Year	%
1970	91.81019
1971	91.30646
1972	90.32445
1973	88.91428
1974	88.09404
1975	86.48078
1976	91.47108
1982	94.81749
1996	98.56956
2010	96.528
2011	97.394
2012	97.35059
2013	97.31431
2014	97.39676
2015	97.57968
2016	97.90418