Windsor Co. decides at the beginning of 2020 to adopt the FIFO method of inventory valuation. Windsor had used the LIFO method for financial reporting since its inception on January 1, 2018, and had maintained records adequate to apply the FIFO method retrospectively. Windsor concluded that FIFO is the preferable inventory method because it reflects the current cost of inventory on the balance sheet. The following table presents the effects of the change in accounting principles on inventory and cost of goods sold. Income taxes are ignored. Inventory Determined by Cost of Goods Sold Determined by Date LIFO Method FIFO Method LIFO Method FIFO Method January 1, 2018 $0 $0 $0 $0 December 31, 2018 90 8 860 942 December 31, 2019 180 260 900 738 December 31, 2020 290 390 1,110 1,090 Retained earnings reported under LIFO are as follows. Retained Earnings Balance December 31, 2018 $1,330 December 31, 2019 2,620 December 31, 2020 3,700 Other information: 1. For each year presented, sales are $3,180 and operating expenses are $990. 2. Windsor provides two years of financial statements. Earnings per share information is not required.