Year	% of revenue
1972	0.886958095755272
1973	0.9242774347513163
1974	0.5821337849280271
1975	0.5968152702389834
1976	0.6150583244962884
1977	0.624760444614795
1978	0.7029682637473738
1979	0.6743562371442705
1980	0.5924549723899468
1981	0.5419385576096851
1982	0.5987726814099277
1983	0.636271585342492
1984	0.6885993609493016
1985	0.6719213594269788
1986	0.6113679568949032
1987	0.7793991416309013
1988	0.7676998546229136
1989	0.7686385574577419
1990	0.9391030240528098
1991	0.7855443348027067
1992	0.9798890016112669
1993	0.6958009304111789
1994	0.7250101689157478
1995	0.7051174003871633
1996	0.6192752709971416
1997	0.5591786955550847
1998	0.42109905665360275
1999	0.39897751915132473
2000	0.4492832259144131
2001	0.38044836634194074
2002	0.4275822085806306
2003	0.45681035225648686
2004	0.5280789545860478
2005	1.2263279123921171
2006	0.6058597173627905
2007	0.49676465262463376
2008	0.5468066491688539
2009	0.610500797217658
2010	0.5587177141366565
2011	0.5823809191604283
2012	0.5763521726994855
2013	0.6004944184265646
2014	0.5901649223112296
2015	0.6257314342837952
2016	0.6356654802874987
2017	0.6345845564235727
2018	0.6626617406162127
2019	0.5978334198642665
2020	0.5982885492449007
2021	0.5951698390875936
2022	0.6259858192547317