Year	% of total
1990	25.2200340810242
1995	14.3146034804412
2000	9.72258872579769
2005	11.4921493284293
2010	12.3100327417112
2011	10.0903091279357
2012	5.28533160257503
2013	3.29139802661375
2014	1.28949168491233
2015	1.28608403858606
2016	0.390193855532173
2017	0.389823476636142