Year	% of total
1990	69.6692545114553
1995	64.9050191793436
2000	63.3434686615888
2005	38.272943738005
2010	22.7094420336726
2011	22.2112800686568
2012	24.7152938283939
2013	34.1825494238088
2014	57.6908091536495
2015	83.2441556371922
2016	82.5797084939636
2017	84.4120206699264