Year	% of revenue
1980	0.3508771929824561
1981	0.37593984962406013
1982	0.34662045060658575
1983	0.41356492969396197
1984	0.42813455657492355
1985	0.7556675062972292
1986	0.9372453137734311
1987	0.6172839506172839
1988	0.6523314810340662
1990	0.6483882919599852
1991	0.5038417936767855
1992	0.5034160373966199
1993	0.5450185306300415
1994	0.5690274008579183
1995	0.46975088967971534
1996	0.562480025567274
1997	0.6153169981320734
1998	0.5808827342980135
1999	0.4997073785621033
2000	0.5657589191471395
2001	0.4748603351955307
2002	0.37263872491145217
2003	0.34635995294732713
2004	0.3584018801410106
2005	0.4412503549662509
2006	0.7469654528478058
2007	0.5547666131365548
2008	0.5354589841115697
2009	0.4737016902934853
2010	0.5679019945826151
2011	4.083001166134811