Year	% of total
1990	99.7201569332738
1995	99.5610527261771
2000	99.4689732857604
2005	80.234989702879
2010	71.6377051612389
2011	74.7175307575752
2012	72.8638153943349
2013	34.2061523319188
2014	43.8458254353608
2015	98.0334837487458
2016	94.5708305558438
2017	94.4196280597213