Year % 2013 7.27006326012274 2014 6.83654700487515 2015 7.27530803959724 2016 6.28615934155792 2017 6.2109555189957 2018 6.01756888201231 2019 6.10710713131734 2020 5.58661427490228 2021 5.34283869762069