Year	% of revenue
1991	20.12141783735692
1993	27.12502400614557
1994	22.634940513462745
1995	26.14230137292163
1996	25.592232790314117
1997	23.319664268640096
1998	24.517011094448726
1999	25.12589451943375
2000	24.053164664416247
2001	24.932425746797005
2002	23.282975203490416
2003	25.252373700187825
2004	27.346890999039232
2005	27.593815403803536
2006	29.011266120358425
2007	27.182067870310046
2008	27.291486250347063
2009	17.19058619089969
2010	13.570869384829523
2011	13.408131805277513
2012	15.048823487280721
2013	15.557107223111593
2014	15.215517032965842
2015	16.142531867850636
2016	16.93404745603519
2017	16.614833828536256
2018	16.830640456233457
2019	26.01249628173506
2020	25.313043493118258
2021	27.59425558490447
2022	28.88317189777841