Year	% of total
1990	27.2607152260844
1995	18.2657478338728
2000	20.4582276731434
2005	17.6624872729994
2010	14.7042791266846
2011	23.1454307020446
2012	15.05800184865
2013	4.68879542377014
2014	3.9265781354132
2015	4.31919456318359
2016	3.10956443907259
2017	3.09734610810042