Year	% of revenue
1990	3.0875173067113604
1991	2.6021529303774584
1992	2.775105454007252
1993	2.2767217370143036
1994	2.4779928126339392
1995	1.8747607936096398
1996	1.5562305030578256
1997	1.447961387696328
1998	1.3742657084567833
1999	1.0987112103103176
2000	1.054505082446659
2001	1.2831697878515653
2002	1.373595529877106
2003	1.2420471069593804
2004	1.1657783026395583
2005	1.2531100876496435
2006	1.264293853957344
2007	1.2817264456583797
2008	1.353828508228451
2009	1.3230727204761767
2010	1.2174381360015873
2011	1.2749451199059483
2012	1.283955687166539
2013	1.2925784172483938
2014	1.3285123723603471
2015	1.451118447648565
2016	1.5018093923032614
2017	1.4445168902136116
2018	1.5961224986095024
2019	1.292463107853818
2020	0.946757009257599
2021	1.1164642114426155
2022	1.263206381612462