Year	% of total
1990	49.4886951327709
1995	43.2963679247823
2000	56.9330077122778
2005	57.7409304156238
2010	58.2342657258758
2011	60.0994624398904
2012	56.8582755503422
2013	46.0031696382002
2014	34.9277268492205
2015	46.1733442295407
2016	34.2351765228229
2017	34.2553043464473