Selected horizontal percentages of a base-year amount from Walla Walla Ltd's statement of income are listed here: 2021 2020 2019 Sales 111% 101% 100% Cost of goods sold 104% 112% 100% Operating expenses 99% 112% 100% Income tax expense 137% 60% 100% Assuming that Walla Walla did not have any non-operating or irregular items, did its net income increase, decrease, or remain unchanged over the period from 2019 to 2021? Net income for Walla Walla in 2020 over 2019. Net income for Walla Walla in 2021 over 2020