Year	% of revenue
2012	7.684026029351071
2013	6.822662838154477
2014	7.289940559735198
2015	9.469374564612227
2016	9.304196272958842
2017	9.133179990294279
2018	7.945559851869646
2019	9.13022983897163
2020	9.081907743980661
2021	9.293917846520303