Year	% of revenue
1995	9.343030802082316
1996	8.851048987514455
1997	8.394983625064423
1998	7.903489784066312
1999	7.08246919434223
2000	6.041262965918158
2001	5.39020458353317
2002	5.878717242353606
2003	5.661005540277684
2004	5.4489113583000055
2005	5.145668513588516
2006	4.9920723124328745
2007	5.137433614010348
2008	4.956528264095694
2009	4.064726551474419
2010	4.013407709179491
2011	3.670565467587564
2012	3.817077751135016
2013	3.236512960138591
2014	2.8934115826734637
2015	2.990060685706969
2016	2.7613811772272485
2017	2.978082441474513
2018	2.958190474567517
2019	2.984825511238149
2020	2.570813421896909
2021	2.5183593903796595
2022	1.976047743400112