Air Croatia reported the following income statement information: (In millions) Net sales Cost of sales 2016 2015 2014 $ 14,617 $ 13,809 S 13,274 11,086 10,484 9,522 Perform a horizontal analysis of net sales, cost of sales, and gross margin, both in dollar amounts and in percentages, for 2016 and 2015 (Round the percentages to two decimal places, X.XX%. Enter negative numbers with a minus sign or parentheses.) Air Croatia Horizontal Analysis of Comparative Income Statement (adapted) For the Years Ended December 31, 2016 and 2015 Increase (Decrease) (Amounts in millions) 2016 2015 2016 2015 2014 Amount % Amount % Net sales S 14.617 S 13,809 $ 13,274 11,086 10,484 9,522 Cost of sales Gross margin 3531 3325 3752