From the following data, calculate the retained earnings
balance as of December 31, 2018:

Retained earnings, December 31, 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $630,900
Decrease in total liabilities during 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137,400
Gain on the sale of buildings during 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48,300
Dividends declared and paid in 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13,500
Proceeds from sale of common stock in 2019 . . . . . . . . . . . . . . . . . . . . . . . . 148,200
Net income for the year ended December 31, 2019 . . . . . . . . . . . . . . . . . . 67,800