Year % of total 1990 99.9999999999606 1995 99.9999999999267 2000 100 2005 99.9999999999948 2010 100 2011 100 2012 99.9999999999948 2013 99.9962164768805 2014 99.9815664183042 2015 99.9962149714443 2016 99.9660913066726 2017 99.9661157279646