Year	% of total
1990	68.0018567431247
1995	69.9208481658112
2000	70.3040978738565
2005	73.3545352724277
2010	74.2779906312133
2011	82.5267090095873
2012	58.7583439169448
2013	49.002354974116
2014	32.9437804953501
2015	33.0029981761349
2016	29.2568576126989
2017	29.2653446223533