Year	% of revenue
1994	8.449032087854091
1998	7.567807309139224
2004	9.614603317905036
2005	10.631608765645117
2006	10.095983233681538
2007	10.291692430758545
2008	10.35579835108435
2009	12.149770816623402
2010	12.419538013339746
2011	11.080575263542137
2012	11.778013272906286
2013	12.835121501549176
2014	11.919615208595648
2015	11.191480719364996
2016	9.649046717953937
2017	9.28879382229199
2018	9.600700483360875
2019	10.193141985181118
2020	10.399366858995414
2021	9.776854344856057
2022	10.032337352392904