What is the change in Net income from Years Ended December 31, 2018 to 2019?
{"Net income": {"2019": 8675, "2018": 13489}, "Weighted average common shares outstanding: -- Class A common stock - basic": {"2019": 89251818, "2018": 88394580}, "Weighted average common shares outstanding: -- Class A common stock - diluted": {"2019": 89658938, "2018": 89045734}}
net_income_2019 = df["Net income"]["2019"]
net_income_2018 = df["Net income"]["2018"]
answer = net_income_2019 - net_income_2018