Year	% of revenue
1992	30.93938692669024
1993	33.20770182146873
1996	32.691216158484494
1997	33.56812297993678
1998	34.53901324851509
1999	33.77967987165029
2001	31.575319735532126
2002	31.513307697718346
2003	29.604188101434364
2004	30.086255431551745
2005	31.490275615841906
2006	35.99789635713027
2007	34.2627978996852
2008	35.480597649070305
2009	36.54595253612929
2010	33.9853675074092
2011	34.82052314824321
2012	34.737775253133904
2013	33.068691070208075
2014	33.77271163215539
2015	31.688571121866126
2016	30.89696314888611
2017	30.15659329102343
2018	30.50566587631917
2019	30.251497657353166
2020	33.11392061051109
2021	33.41965271923594
2022	34.39536284226149
