Common-size and trend percentages for a companys net sales, cost of goods sold, and expenses follow: Common-Size Percentages Trend Percentages 2023 2022 2021 2023 2022 2021 Net sales 100.0 % 100.0 % 100.0 % 107.6 % 106.1 % 100.0 % Cost of goods sold 74.0 70.8 67.7 114.8 110.9 100.0 Expenses 19.9 17.7 18.7 111.4 105.0 100.0 Required

: a. Calculate the profit percentage for 2021, 2022 and 2023. (Round the final answers to 2 decimal places.)

b. Determine whether the companys profit increased, decreased, or remained unchanged during this three-year period.