Year	% of total
1990	95.2272335171757
1995	95.47398537535965
2000	96.4544096478489
2005	96.07490641467153
2010	96.55062174593178
2011	97.00504684253217
2012	94.95402858250618
2013	94.29082774720001
2014	91.08683674501302
2015	90.21387466635169
2016	87.14450263733706
2017	87.16068272979977