Vertical analysis (common-size) percentages for Palau Company's sales revenue, cost of goods sold, and expenses are as follows. Vertical Analysis 2020 2019 2018 Sales revenue 100.0 % 100.0 % 100.0 % Cost of goods sold Expenses 56.5 60.2 63.8 20.0 23.2 26.4 Calculate the net income as a percent of sales for each year. (Round answers to 1 decimal place, e.g. 12.5%.) Net income 2020 % 2019 % 2018 % Did Palau's net income as a percent of sales increase, decrease, or remain unchanged over the 3-year period?