Year % 2009 3.46095790428879 2010 3.34951747323682 2011 2.52887904557003 2012 2.20068041783046 2013 2.44086452225224 2014 2.02468665436274 2015 1.8854782076355 2016 1.71584803855675 2017 1.5793111524775 2018 1.67363606149179 2019 1.97428417462379 2020 3.53246213156459 2021 3.95540769439997