A Company Reports the Following Comparative Income Statements What Are the Costs of Goods Sold in Common-Size Percents

A company reports the following comparative income statements:
$\begin{array}{|l|r|r|}\hline &{2014} &{2013} \\\hline \text { Net sales } & \$ 736,000 & \$ 840,000 \\\hline \text { Cost of goods sold } & \underline{518,880} & \underline{571,200} \\\hline \text { Gross profit } & \$ 217,120 & \$ 268,800 \\\hline \text { Operating expenses } & 104,800 & 130,000 \\\hline \text { Net income } & \$ 112,320 & \$ 138,800 \\\hline\end{array}$ What are the costs of goods sold in common-size percents for 2013 and 2014, respectively?