Year	% of total
1990	96.6384415652736
1995	96.505413168743
2000	96.1389967782658
2005	96.2730120903714
2010	96.1691766642551
2011	96.6888571045226
2012	96.1738738296923
2013	96.1889418588319
2014	96.2078839658759
2015	96.2276345410767
2016	96.2459478860909
2017	96.2627004530301