Year % of total 1990 4.64156380047368 1995 0 2000 2.48578917624871E-11 2005 2.46358351317824E-11 2010 2.41806657771299E-11 2011 2.41029493848674E-11 2012 0 2013 0 2014 0 2015 0 2016 0 2017 0