Year	% of total
1990	99.41028146227559
1995	99.431754669702
2000	99.45708517063328
2005	99.5240787022548
2010	99.4459043634793
2011	99.56783254955978
2012	99.440023977287
2013	99.09396977955672
2014	98.72372507616589
2015	98.72973464015801
2016	98.1710999611896
2017	98.06774115133952