Year	% of revenue
1973	1.9635545498399885
1974	1.682912700486627
1975	1.5841991564653841
1976	1.5197568389057752
1977	1.976784896717029
1978	1.7625875728409635
1979	1.721093972999544
1980	1.5582575847007485
1981	1.4035087719298238
1982	1.5276322506112243
1983	2.030609094517708
1984	1.7413447829705875
1985	1.9576372597291616
1986	1.8152114296542052
1987	2.176704191697979
1988	2.0900221081002806
1989	1.4479559543937266
1990	1.8361826002532449
1991	2.5687588764297726
1992	2.151698330454807
1993	2.9309676727869336
1994	2.0879936474286636
1995	2.589976712800624
1996	2.528727062436741
1997	2.4891206743620824
1998	2.446939050127199
1999	2.4985257146404294
2000	2.3725181870021252
2001	1.669512927359115
2002	2.1006063113671445
2003	1.9187409475743231
2004	1.8446829322054912
2005	2.077589271243773
2006	1.9989808695138318
2007	1.9490997964506627
2008	1.903154773237766
2009	1.599868132703866
2010	1.262450770492336
2011	1.288297775011167
2012	1.2101352246549295
2013	0.9331558609360151
2014	0.9516578355986282
2015	0.7849527908741463
2016	0.6009266482124268
2017	1.1938051324166046
2018	0.7101991011503793
2019	0.6967220622227318
2020	0.7188254705995633
2021	0.7516474119067214
2022	0.7481329762200122