Year	% of total
1990	94.81507920072995
1995	94.22869297452053
2000	93.98694202590882
2005	93.8603098667348
2010	93.60499757502357
2011	94.36023905358529
2012	92.27699370242098
2013	91.0791605658262
2014	88.30788177023591
2015	88.60856820159515
2016	85.06739705197316
2017	85.05041806672105