BE14-5 Vertical analysis percentages from Waubon Corp.'s income statement are listed here: 2018 2016 100.0% 2017 100.0% 60.5% 100.0% 59.4% 60.0% Net sales Cost of goods sold Operating expenses Income tax expense 19.6% 20.4% 20.0% 4.2% 3.8% 4.0% Assuming that Waubon did not have any non-operating or irregular items, did its net income as a percentage of sales increase, decrease, or remain unchanged over the three-year period? Explain. Calculate and evaluate liquidity. (LO 2)