Year % of total 1990 99.9999999956397 1995 99.9999999959046 2000 100 2005 100 2010 100 2011 100 2012 100 2013 99.9999999992591 2014 99.9942643385562 2015 99.978648421315 2016 93.6940546750848 2017 82.8031823467088