Year	%
1981	87.59621
1982	90.36956
1983	91.34763
1985	96.99691
1987	96.4603
1990	97.58226
1991	99.0812
1992	99.34457
1999	99.84211
2000	99.27656
2001	99.19103
2002	99.36167
2003	99.21005
2004	99.02273
2011	99.79041
2012	99.92808
2013	99.82811
2014	99.87832
2015	99.99489
2016	99.35795
2017	99.4653