Year % 2009 21.1415508110567 2010 18.31 2011 14.3983059633084 2012 11.7263814541696 2013 10.5639712164989 2014 9.9349604753277 2015 9.76734535087824 2016 12.0891590616386 2017 12.9585022894491 2018 12.6974012595366 2019 14.7557610602629 2020 16.3638896305079