Year	% of revenue
1972	1.870503597122307
1973	1.781472684085508
1974	1.673640167364013
1975	1.4061207609594721
1976	0.9208103130755038
1977	0.8277289187790989
1978	0.5319148936170226
1979	0.4398826979472143
1980	0.5352112676056326
1981	0.38400722837135814
1982	1.1057606563224476
1983	2.2713321055862545
1984	2.8241513633834066
1985	2.6326078456926956
1986	1.9467470484802887
1987	1.938929525136426
1988	1.9881145326850358
1989	1.6033573657591713
1990	1.6662534093726824
1991	1.7463074787915565
1992	1.574376612209806
1993	2.3564083560150895
1994	2.1420563369723324
1995	3.125506971638612
1996	3.3029057257945014
1997	3.6735724865876973
1998	3.9592310321500546
1999	3.763832135603766
2000	1.1858729418969938
2001	1.5644347315839875
2002	1.4072716451381726
2003	1.8446056006646117
2004	1.6958995081688015
2005	1.361393099925361
2006	1.3281981062748809
2007	1.4967842432953884
2008	1.614882357802641
2009	1.8490866589963684
2010	1.8881118746158216
2011	2.690757576042409
2012	2.8393358636759745
2013	2.9405505203512368
2014	3.2203048963317964
2015	2.213958688328742
2016	1.9443344362403383
2017	1.9389210344627712
2018	2.0834499937567785
2019	2.2170680027054157
2020	2.302897654574581
2021	2.4140848531971506
2022	1.9172907954178129