15. From 2021 to 2022, did The Hershey Company's net profit margin increase, decrease or remain the same?

\begin{tabular}{lcccccc} Currency in USD & & & & & & Download \\ Date & Open & High & Low & Close* & Adj Close** & Volume \\ \hline Dec 30, 2022 & 233.07 & 233.42 & 229.83 & 231.57 & 227.03 & 441,400 \end{tabular} \begin{tabular}{|c|c|c|c|c|c|c|c|c|} \hline \multirow[b]{2}{*}{ For the years ended December 31, } & & & \multirow{2}{*}{\multicolumn{2}{|c|}{2021}} & \multirow{2}{*}{\multicolumn{2}{|c|}{2020}} & \multicolumn{2}{|c|}{ Percent Change } \\ \hline & & & & & & & 2022 vs 2021 & 2021 vs 2020 \\ \hline In millions of dollars except per share amounts & & & & & & & & \\ \hline Net sales & $ & 10,419.3 & s & 8,971.3 & s & 8,149.7 & 16.1% & 10.1% \\ \hline Cost of sales & & 5,920.5 & & 4,922.7 & & 4,448.5 & 20.3% & 10.7% \\ \hline Gross profit & & 4,498.8 & & 4,048.6 & & 3,701.2 & 11.1% & 9.4% \\ \hline Gross margin & & 43.2% & & 45.1% & & 45.4% & & \\ \hline SM\&A expense & & 2,236.0 & & 2,001.4 & & 1,890.9 & 11.7% & 5.8% \\ \hline SMEA expense as a percent of net sales & & 21.5% & & 22.3% & & 23.2% & & \\ \hline Long-lived asset impairment charges & & - & & - & & 9.1 & NM & NM \\ \hline Business realignment costs & & 2.0 & & 3.5 & & 18.5 & (43.6)% & (80.9)% \\ \hline Operating profit & & 2,260.8 & & 2,043.7 & & 1,782.7 & 10.6% & 14.6% \\ \hline Operating profit margin & & 21.7% & & 22.8% & & 21.9% & & \\ \hline Interest expense, net & & 137.6 & & 127.4 & & 149.4 & 8.0% & (14.7)% \\ \hline Other (income) expense, net & & 206.1 & & 119.1 & & 138.3 & 73.1% & (13.9)% \\ \hline Provision for income taxes & & 272.3 & & 314.4 & & 219.6 & (13.4)% & 43.2% \\ \hline Effective income tox rate & & 14.2% & & 17.5% & & 14.7% & & \\ \hline Net income including noncontrolling interest & & 1,644.8 & & 1,482.8 & & 1,275.4 & 10.9% & 16.3% \\ \hline Less: Net gain (loss) attributable to noncontrolling interest & & & & 5.3 & & (3.3) & NM & NM \\ \hline Net income attributable to The Hershey Company & $ & \begin{tabular}{ll} 1,644.8 \\ \end{tabular} & =s & 1,477.5 & =s & 1,278.7 & 11.3% & 15.5% \\ \hline Net income per share-diluted & $ & 7.96 & s & 7.11 & s & 6.11 & 12.0% & 16.4% \\ \hline \end{tabular}