Year	% of total
1990	99.9928995249183
1995	99.9921464808226
2000	99.9971243149578
2005	99.9971104727318
2010	99.9970567210338
2011	99.9970599725855
2012	99.9970688030397
2013	99.997080985383
2014	99.9970944856033
2015	99.9971074649768
2016	99.9971186009184
2017	99.9971280127308