Year % 2011 21.2568152337493 2012 7.06540793782702 2013 6.67915282830046 2014 7.06684982304958 2015 6.33586520518742 2016 16.5034214266212 2017 6.86150898089956 2018 7.00625001241205 2019 7.40992674549429 2020 6.81670716392261