Year	% of revenue
1990	1.9473734207276525
1991	2.3143475126171595
1992	2.072583792221307
1993	1.885135530706633
1994	1.4536827348215249
1995	1.1725889897456552
1996	1.0631998631524928
1997	0.9830255341439765
1998	1.0052829200139712
1999	0.0020603051311899293