What was the increase / (decrease) in the net revenues from March 31, 2019 to December 31 2019?
{"": {"March 31,": "", "June 30,": "(In thousands, except per share amounts)", "September 30,": "", "December 31,": ""}, "Net revenues": {"March 31,": 338649, "June 30,": 333532, "September 30,": 333326, "December 31,": 331035}, "Operating income": {"March 31,": 16720, "June 30,": 14300, "September 30,": 23542, "December 31,": 26719}, "Net income (loss) attributable to common stockholders": {"March 31,": -7265, "June 30,": -7387, "September 30,": 257, "December 31,": -5988}, "Basic and diluted earnings (loss) per share": {"March 31,": -0.11, "June 30,": -0.1, "September 30,": "$\u2014", "December 31,": -0.08}}
net_revenues_dec_31 = df["Net revenues"]["December 31,"]
net_revenues_mar_31 = df["Net revenues"]["March 31,"]
answer = net_revenues_dec_31 - net_revenues_mar_31