Ford Motor Company is the worlds second-largest producer of cars and trucks and ranks among the largest providers of financial services in the United States. The following information pertains to Ford: (in millions)

(in millions)	1998	1999	2000
Sales	$118.017	$135,073	$141,230
Cost of goods sold	104,616	118,985	126,120
Gross margin	$ 13,401	$ 16,088	$ 15,110
Operating expenses	7,834	8,874	9,884
Net operating income	$ 5,567	$ 7,214	$ 5,226

Prepare a statement showing the trend percentages for each item, using 1998 as the base year.

Comment on the trends noted in part (a).