Year	% of total
1990	0.00165738402471138
1995	0.00178113858303464
2000	0.0480812007024767
2005	0.0501378437072209
2010	0.0525020167761014
2011	0.0529649149912825
2012	0.0533978423912451
2013	0.0537820740773465
2014	0.016386108728117
2015	0.0515474597732268
2016	0.0164458492829311
2017	0.0164350247258471