Year	% of total
1990	66.8522477077851
1995	54.0881080712426
2000	46.0706654804032
2005	29.5905257235759
2010	41.5793663305012
2011	27.5301469392753
2012	20.0639998807775
2013	42.4337373882219
2014	33.3736272469654
2015	52.250520986808
2016	77.5389871393223
2017	76.9575511780133