Year	% of revenue
1992	47.43463246176611
1993	47.33446519524616
1994	43.54183590576748
2002	37.70923192341424
2003	37.66994237477803
2004	37.458826057886476
2005	37.45652769376313
2006	37.42075083881772
2007	37.712503345196744
2008	38.30383899088447
2009	41.01686274682148
2010	41.1874125361699
2011	40.95313880753192
2012	40.63116084241208
2013	39.36690224744517
2014	38.928906068952365
2015	38.30523088593192
2016	39.797157923208566
2017	40.05067117746154
2018	39.87777195214504
2019	40.356031614608796
2020	44.0705682257305
2021	41.562907331049686
2022	41.37628708091829