Year	% of total
1990	59.3593949452541
1995	52.6617487727791
2000	48.3955542819081
2005	44.5444864638872
2010	43.2644701287918
2011	52.9726136122272
2012	43.7081411787059
2013	32.2706654007732
2014	32.2043820071039
2015	30.8545215416116
2016	18.0796884803149
2017	21.2219312438144