Year % 2012 11.5343664524884 2013 15.3368529632838 2014 18.7296683852754 2015 19.9548869569175 2016 22.4733058554676 2017 16.5213170516291 2018 18.0601133582426 2019 16.0366062911771 2020 13.2506636381681 2021 6.68666401909928