Year	% of total
1990	8.81083310710187
1995	5.12408292165938
2000	2.94858826039928
2005	2.36871514851381
2010	2.3042528954796
2011	3.12760302284407
2012	2.31050995112519
2013	0.102271877700189
2014	0.109959389851821
2015	0.109980365008411
2016	0.109388684701661
2017	0.108280911899017