Year	% of revenue
2012	0.5926389864180921
2014	0.6720609790722405
2015	1.0118688362915123
2016	1.2469471073810814
2017	1.4274634117916971
2018	1.5612802431344357
2019	1.6936602539524725
2020	1.4881897424981942
2021	1.3287374833161634
