Year % 2009 8.56654508720971 2010 8.799975245355 2011 8.84510172420863 2012 8.81227893874936 2013 9.15159721181849 2014 9.20274538590688 2015 9.36191741166209 2016 9.33143961937975 2017 9.37951712686412 2018 9.4405074456163 2019 9.39570266980086 2020 8.6063941052102 2021 8.62368627738747 2022 8.57788925795035