Year	% of total
1990	96.1373331798487
1995	96.451547821848
2000	97.1340927424942
2005	97.5344542517827
2010	97.4256245114871
2011	97.5939188636845
2012	91.600126669684
2013	95.6600539353696
2014	78.0399867456251
2015	83.1713587316365
2016	49.4349080683845
2017	52.963341242938