Year Percent 2011 18.79328 2012 21.31119 2013 23.93104 2014 26.65282 2015 29.47654 2016 32.4022 2017 35.4298 2018 38.55933 2019 41.7908 2020 41.7908 2021 41.7908 2022 41.7908