Express Rivera Company€™s partial comparative income statements as common-size statements, and comment on the changes from 2013 to2014.

Rivera Company Partial Comparative Income Statements For the Years Ended December 31,2014 and 2013 Net sales Cost of goods sold Gross margin Selling expenses General expenses Total operating expenses Operating income 2014 S424,000 254,400 $169,600 $106,000 2013 $368,000 239,200 $128,800 $ 73,600 50,880 36,800 $156,880 12,720 $110,400 S 18,400