Year	% of revenue
1995	20.639626334722287
1996	18.55013109873586
1997	17.979283322063534
1998	18.828412959336053
1999	16.708979981017208
2000	17.95208400285083
2001	17.699184415143115
2002	16.647485547972266
2003	19.268609991539627
2004	18.462485146834155
2005	16.856878020797172
2006	19.461292991684246
2007	18.011004783080732
2008	19.942716670064183
2009	19.71838478437193
2010	19.941318764041448
2011	18.195095003398656
2012	18.611991770675576
2013	18.773009318110528
2014	19.06630792058091
2015	19.927421202929313
2016	20.783105161284226
2017	20.822191775445077
2018	20.611589614693663
2019	21.88491500687322
2020	21.15158294902932
2021	20.389778755771196
2022	23.39502984220071