Year % 2009 8.18222996575437 2010 8.09100817591632 2011 12.0810518467523 2012 16.964363970331 2013 17.4978622038032 2014 16.6112764865 2015 17.6113939029 2016 15.4489088582062 2017 12.9710977197129 2018 13.7365293816121 2019 12.1762298867312