Year % 2008 6.76557787144259 2009 7.08666781955874 2010 6.59282558490416 2011 6.39806045184222 2012 7.02289614603664 2013 7.2249759721181 2014 7.69096399838565 2015 7.66968696675763 2016 7.50499734854729 2017 7.29875378491429 2018 8.96818751362541 2019 9.32702816597098 2020 8.88828769731785 2021 8.18252567378343 2022 7.89714683542292