Year	% of revenue
2014	1.5515648321471556
2015	1.6318913698699915
2016	2.8123671327557958
2017	2.2425860842721295
2018	3.123357720551306
2019	0.7955511016094428
2020	2.431769137717001
2021	1.7799403942602092