Year	% of total
1990	26.2514265817528
1995	26.9408804785216
2000	25.9360509859805
2005	25.0646194384755
2010	18.699827857653
2011	29.7626937385515
2012	18.7361348951765
2013	18.7687463488334
2014	0
2015	0
2016	0
2017	0