Year % of total 1990 83.4055575466791 1995 84.3654661729512 2000 89.8168301152672 2005 77.4844165887647 2010 85.458456172196 2011 93.2619073538502 2012 60.5084303300629 2013 55.3899443443635 2014 28.7357806063166 2015 26.4441570195712 2016 22.3952430687433 2017 22.3857446597034