Year	% of revenue
2013	0.2902516591441455
2014	0.03808085367704412
2015	0.07736236747645996
2016	0.08127801970077428
2017	0.05652431988411175
2018	0.0627095095756303
2019	0.06950673191840194
2020	0.07487409433617198