Year % 2012 4.53505751255773 2013 5.33995094763897 2014 5.61507541855652 2015 6.00001242462912 2016 6.15140677490154 2017 6.05560632654632 2018 6.04633140039262 2019 6.09899130680541 2020 5.91090648276954 2021 5.78324237360126 2022 5.51814215557498