Year	% of total
1990	46.6870602413446
1995	40.5449071431562
2000	37.3975259088191
2005	13.81206659319
2010	19.2944358201435
2011	24.0124118597135
2012	23.811694328521
2013	10.9490874546926
2014	11.8553860903789
2015	72.4891318213699
2016	68.0017667432415
2017	68.568592601686