Year % 2009 10.4864062831784 2010 9.50393611887601 2011 8.54144378847603 2012 6.21245513449301 2013 7.26079589253585 2014 6.20788397259295 2015 6.91745044731219 2016 6.21559255247132 2017 6.50251723428062 2018 6.20194384933339 2019 4.24107106191948 2020 4.01829638034386 2021 5.14185685831727