Year	%
1970	91.67054
1971	90.65974
1972	90.72993
1973	88.73865
1974	88.8015
1975	87.17127
1976	91.2165
1982	95.55964
1996	99.19605
2010	97.3883
2011	98.13074
2012	98.2866
2013	97.95218
2014	98.06903
2015	98.20181
2016	98.43546