Year	% of total
1990	75.9974546591054
1995	51.6995821382151
2000	40.8895406300352
2005	31.7318392849113
2010	45.9226250417122
2011	38.7908954862943
2012	20.2294079729242
2013	15.66608691596
2014	11.3814028036792
2015	12.6505845090687
2016	6.80445513089125
2017	6.80292593846394