Year	%
1991	88.87791
1999	80.44303
2000	79.65374
2001	89.72346
2002	87.89453
2003	85.60561
2007	87.92562
2012	86.21871
2013	87.51016
2014	87.29895
2015	87.46915
2016	82.38135