Year	% of revenue
1976	1.0176754151044456
1977	2.5480203841630735
1978	2.8112449799196786
1979	2.6618468616496878
1980	2.423154588288086
1981	2.5531121878494223
1982	3.3922771562612772
1983	4.36289500509684
1984	3.690248565965583
1985	3.9711858145548575
1986	7.459765115267508
1987	7.82608695652174
1988	8.42185128983308
1989	8.98366606170599
1990	7.597494443321883
1991	8.060701616081985
1992	7.428799044015136
1993	8.343688975679035
1994	9.034267912772584
1995	11.176261549395877
1996	10.157728706624605
1997	4.852941176470589
1998	13.066233531853456
1999	11.25904486251809
2000	7.478790114348949
2001	7.601351351351352
2002	5.1477040070195965
2003	4.804332634521314
2004	3.9422501496110116