Year	% of revenue
1972	2.5480387114872127
1973	2.0209887677297695
1974	1.822635256825877
1975	1.5841991564653841
1976	1.6813476499710667
1977	1.976784896717029
1978	1.2722951724800153
1979	1.1092464491834144
1980	1.1742507510808238
1981	1.0628487472451897
1982	1.212837889055654
1983	0.9275699504071512
1984	0.8394587370531239
1985	0.8136963800619117
1986	0.8480445162622863
1987	0.8254379987250225
1988	0.7905918530600372
1989	0.8379914958673738
1990	1.0611252348844922
1991	0.9657670087091489
1992	0.9700252673843066
1993	1.0163931777233763
1994	1.144725468826337
1995	1.0287291431438967
1996	1.123507382208192
1997	1.1918986916134766
1998	1.3399813025864755
1999	1.4580763679307178
2000	1.3753638716895973
2001	1.3535850172071062
2002	1.3313740003842263
2003	1.1429407132270424
2004	1.1958651777274762
2005	1.0686209999571081
2006	1.0810043269302285
2007	0.9798694590743756
2008	1.0798401639410027
2009	0.9082997559299709
2010	0.6106423472348317
2011	0.3716258786327836
2012	0.5168442037890916
2013	0.6595611946197857
2014	0.5657455787974945
2015	0.5808875481858895
2016	0.5749542848116095
2017	6.803001578131215
2018	0.6274113232541764
2019	0.4351096530811767
2020	0.5034658623735976
2021	0.6185949898285446
2022	0.6516728449870786