Common-size and trend percentages for a company's net sales, cost of goods sold, and expenses follow: Common-Size Percentages Trend Percentages 2020 Net sales 100.0% 2019 100.0% 2018 100.0% 2020 2019 2018 108.5% 107.3% 100.0% Cost of goods sold Expenses 55.8 53.3 49.6 32.4 30.3 30.7 115.2 111.9 110.7 104.6 100.0 100.0 Required: a. Calculate the profit percentage for 2018, 2019 and 2020. (Round the final answers to 2 decimal places.) Profit Percentage 2018 % 2019 % 2020 % b. Determine whether the company's profit increased, decreased, or remained unchanged during this three-year period. Profit