Year	% of revenue
1996	38.36760585716551
1997	23.693379790940767
1998	26.949006050129647
1999	24.499012136607394
2000	22.885640114769778
2001	29.049868532465794
2002	29.0280426644063
2003	26.816505801973754
2004	26.596028468687642
2005	23.691398091320973
2006	27.62762176307464
2007	26.55731748462277
2008	29.0955088921463
2009	33.40888616281076
2010	30.305574483273308
2011	30.5272681915159
2012	30.791122796270997
2013	30.19930366399458
2014	27.996030663642905
2015	30.18432606250062
2016	31.4795012293809
2017	31.345539486791935
2018	31.945618615252265
2019	31.4156761730159
2020	33.14904653988332
2021	30.49675398577591
2022	29.392507052352514