Year	% of total
1990	46.0285361415029
1995	44.0893251411402
2000	38.7767655955145
2005	21.3793406705815
2010	22.8635613087028
2011	21.817609254149
2012	27.5962681461697
2013	5.93723416421001
2014	6.99387174369358
2015	64.3106073965477
2016	51.4548309192976
2017	52.0663820359692