Year	% of revenue
2003	33.09119662048285
2004	30.11409531502423
2005	33.75856748227302
2006	36.782853858711974
2007	36.956686312791646
2008	34.21854271985818
2009	32.261529904084526
2010	31.642147953337417
2011	29.72252520660652
2012	30.748663849763457
2013	27.631920423209827
2014	28.90900956389058
2015	29.66103736421801
2016	29.982734008462575