Year	% of revenue
1994	12.384126781774066
1997	12.876013489025498
1998	13.215036497892523
1999	13.954307346920809
2000	15.88158357342759
2001	16.714427975237292
2002	16.585762010023767
2003	14.51587183465876
2004	15.764516224689784
2005	14.176322199584138
2006	14.130410413884114
2007	15.360239472772141
2008	14.631016836015723
2009	15.826001500626226
2010	15.061127359261747
2011	14.487360809496508
2012	14.116488972774102
2013	15.382350632016959
2014	16.948540728213953
2015	19.520755485717455
2016	17.687070517309586
2017	18.15694693506718
2018	18.565491305173097
2019	18.638965118447697
2020	16.93263885018424
2021	17.461004624711755
2022	16.03400565822536