Year	%
1972	94.81463
1973	97.33511
1974	97.50499
1976	84.74591
1977	99.89846
1978	99.56575
1979	99.64034
1981	99.96485
1982	99.05678
1983	99.57972
1984	99.24644
1994	99.72109
1996	97.18101
1998	97.05168
1999	99.05356
2000	99.62126
2001	99.57514
2002	99.18004
2003	99.16808
2004	96.82238
2009	99.74267
2011	99.35773
2012	98.32508
2015	99.67938
2016	97.11416
2017	97.79018