Year % 2008 2.15099820496032 2009 1.79656609383679 2010 2.09259938242001 2011 2.79209384764478 2012 3.43791016533393 2013 3.10707263260723 2014 3.49733108025613 2015 2.75511790461508 2016 2.63885944068427 2017 2.11141959192174 2018 2.12656065140467 2019 1.77330386734804 2020 1.87185415971075 2021 1.59911146644285