Year	% of revenue
1990	42.2267663993973
1991	41.6859437465153
1992	42.688995215311
1993	46.49218397715316
1994	48.316496893359826
1995	49.485153833968134
1996	51.11505091438071
1997	51.031910195923494
1998	50.34227211593885
1999	50.524534186009795
2000	56.75057419739451
2001	57.00386751165052
2002	56.12476497951295
2003	53.667984912883156
2004	59.842773092702004
2005	55.28283536296983
2006	51.132202774577415
2007	48.09248185756974
2008	44.63473861621807
2009	37.54076128153745
2010	42.60022903728974
2011	42.915749481270474
2012	46.151682759913754
2013	43.95227649114288
2014	45.40993958891647
2015	49.58134969154088
2016	49.644942062022345
2017	55.64889404364622
2018	54.805285838982556
2019	51.180633065865436
2020	41.59311052709953
2021	43.93234029324141
2022	43.37092305431015