Year	% of total
1990	70.7833103104291
1995	41.1390662923512
2000	24.8940709012521
2005	24.2860716237424
2010	30.9071744745651
2011	24.6908730603563
2012	19.8946446188652
2013	16.6071155078203
2014	14.1014568388838
2015	12.157721772811
2016	8.31280284277071
2017	8.30417717411434