Year	% of revenue
2003	15.009740188675117
2004	13.71668012924071
2005	13.801128053562477
2006	14.607586828943134
2007	15.353815024482827
2008	15.055605508347739
2009	16.99655321162347
2010	20.266276378966175
2011	20.290992945735724
2012	23.281818340716793
2013	25.845325047548933
2014	26.903662692649927
2015	26.165453546704537
2016	25.6330743491592