Year	% of revenue
1991	3.0836809877199887
1992	6.659581756518543
1993	6.154605093412128
1994	7.171393913080023
1995	3.9443891119571113
1996	3.5221623581068897
1997	3.9870437077045375
1998	3.0184138171463646
1999	2.957505233316828
2000	2.109170094002552
2001	1.3597770541620924
2002	1.3354063724654968
2003	1.2950102309565859
2004	0.42437441529485076
2007	0.028453471322154054
2008	0.010489763513883147
2009	0.007129637903315691
2010	0.007272056153159829