Year	% of revenue
1990	2.1215287672967924
1991	2.79379956741168
1992	1.7777392360057234
1993	2.9184473976933436
1994	2.9548150544591825
1995	2.619350041822857
1996	2.7593194468202693
1997	2.5757052260847275
1998	2.5617796018162764
1999	2.4589741740751805
2001	0.528685044331017
2002	0.4567503257335203
2003	0.4474118942731278
2004	0.3549538124898984
2005	0.45159552035987066