Common-size and trend percentages for a company's net sales, cost of goods sold, and expenses follow. Common Size Percentages 2020 2019 2018 100.0% 100.0% 100.0% 66.7 63.6 60.7 18.9 16.6 18.6 Trend Percentages 2020 2019 2018 108.6% 107.1% 100.0% 116.7 111.4 100.0 111.1 104.5 100.0 Net sales Cost of goods sold Expenses 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. Proll