Year % of total 1990 99.9999999995859 1995 99.9999999994829 2000 99.9999999999611 2005 99.999999999963 2010 99.9999999999652 2011 99.9999999999771 2012 99.9999999999662 2013 99.9999999999555 2014 99.9999999999233 2015 99.9999999999459 2016 99.9999999998609 2017 99.9999999998623