Year % 2008 0.50936574866239 2009 3.81668671640444 2010 2.42280900203523 2011 1.49105437766406 2012 1.32547589221842 2013 1.27694211466818 2014 1.27782210089718 2015 1.59817495618485 2016 2.31586181233161 2017 2.37168098623647 2018 2.2553221144042 2019 0.764833930030631 2020 0.656687610770611