Year	% of total
1990	98.7887191349441
1995	98.7817045295855
2000	98.9188408794683
2005	98.9457816829331
2010	98.9795652083124
2011	99.1951885317321
2012	98.7806680279361
2013	98.7429528896444
2014	98.1719550704895
2015	97.9791966245288
2016	97.181663084537
2017	97.1618884510276