Year	%
1981	87.10191
1982	86.44628
1983	91.46552
1985	96.9697
1987	95.0137
1990	97.13492
1991	98.20076
1992	98.71717
1999	100
2000	98.5705
2001	98.41401
2002	98.75906
2003	98.57471
2004	98.34636
2011	99.79347
2012	100
2013	99.66881
2014	99.76448
2015	100
2016	99.28571
2017	99.36462