Year	% of revenue
1996	68.30702497706366
1997	74.44484875539959
1998	65.25363388141669
1999	55.61397887835334
2000	69.38555797752075
2001	68.17533364498587
2002	74.50898486684706
2003	78.53657030800733
2004	82.26241218945017
2005	79.00239324851997
2006	79.55217720299925
2007	79.06919742038885
2008	84.79503045522672
2009	83.13971023454312
2010	89.30806983277141
2011	90.08774105827027
2012	90.55876121550564
2013	91.28552475385797
2014	89.47887821029997
2015	83.66804410215057
2016	83.3159721127751
2017	83.42368698439843
2018	86.87207672941665
2019	82.84051792907917
2020	60.33183050061861
2021	63.1265616778282
2022	53.437504462322494