Year	% of total
1990	34.6835137225067
1995	39.0423840689999
2000	56.5812943752904
2005	56.7716777694375
2010	52.5401886013223
2011	60.9901742934895
2012	50.3829864129099
2013	47.9547009661018
2014	33.5233531294471
2015	27.7369005348759
2016	17.7014306605328
2017	18.6246966771059