Year % 2012 5.71026349860104 2013 7.12373619141485 2014 6.38267849950904 2015 5.09174595659944 2016 4.71813279786195 2017 4.46120203086986 2018 3.68642493378735 2019 3.15282728174409 2020 2.85122667258747 2021 2.91575876060378 2022 3.06045808223842