Year	% of revenue
1991	0.41208791208791096
1992	6.942689603783969
1993	2.704358375288683
1994	3.1126705657290623
1995	2.6616893041179535
1996	3.02153755121627
1997	2.7306896253023365
1998	3.080400436266794
1999	3.841312765264447
2000	5.236494126913728
2001	5.547798537640328
2002	4.187133259047041
2003	4.197890140662543
2004	4.620243836144357
2005	4.703919209658401
2006	4.483862093280601
2007	4.317661881340077
2008	4.590724435528096
2009	6.031554058327191
2010	6.6624312837841035
2011	7.479311711912112
2012	8.556134603052078
2013	8.543254578072258
2014	9.11012132075221
2015	8.850469888584275
2016	7.839428868570438
2017	6.718472094356553
2018	5.951794086042403
2019	5.525863157569854
2020	4.953864118471569
2021	3.8235232746223655
2022	3.7692295364736332