Help with percentages please! I keep getting them wrong

Analyze Amazon.com Amazon.com, Inc. (AMZN) is the largest Internet retailer in the United States. Amazon's income statements for two recent years follow: Amazon.com, Inc. Income Statements For the Years Ended December 31 (in millions) Year 2 Year 1 Revenues: Product sales $94,665 $79,268 Service sales 41,322 27,738 Total revenues $135,987 $107,006 Operating expenses: Cost of sales $(88,265) $(71,651) Fulfillment (17,619) (13,410) Marketing (7,233) (5,254) Technology and content (16,085) (12,540) General and administrative (2,432) (1,747) Other operating expense (income), net (167) (171) Total operating expenses $(131,801) $(104,773) Operating income $4,186 $2,233 a. Prepare a horizontal analysis of the income statements. Round percentages to one decimal place. Amazon.com, Inc. Income Statements For the Years Ended December 31 (in millions) Increase/(Decrease) Year 2 Year 1 Amount Percent Revenues: Product sales 0.2% Service sales $94,665 41,322 $135,987 $79,268 $ 27,738 $107,006 $ 15,397 13,584 28,981 Total revenues 2.7 Operating expenses: Cost of sales Fulfillment Marketing $(88,265) $(71,651) $ (17,619) (13,410) (7,233) (5,254) (16,085) (12,540) (2,432) (1,747) (167) (171) $(131,801) $(104,773) $ $4,186 $2,233 $ 16,614 4,209 1,979 3,545 685 Technology and content General and administrative Other operating expense (income), net -4 Total operating expenses 27,028 1,953 2.6 8.7 Operating income