Year % of total 1990 99.9999999999999 1995 99.9999999999999 2000 99.9999999999999 2005 99.9999999999999 2010 99.9999999999999 2011 99.9999999999999 2012 99.9999999999999 2013 99.9999999999999 2014 99.9999999999999 2015 99.9999999999999 2016 99.9999999999999 2017 99.9999999999999