Year	% of revenue
1992	11.64282190429206
1993	10.882852292020395
1994	12.293528296777685
2002	13.31226027324887
2003	13.78056605746209
2004	14.186813124505393
2005	15.60932324549538
2006	16.693709513538398
2007	15.950987199788042
2008	14.918047538154045
2009	12.215518551240503
2010	10.994028488608716
2011	10.680468778551464
2012	9.378827824990724
2013	7.934945565716762
2014	8.758685438977976
2015	9.661746578589716
2016	10.803222267442889
2017	11.116878099225143
2018	12.109708820622272
2019	12.090249666529592
2020	11.408030428513113
2021	13.356550878734197
2022	12.957794612345557