What was the percentage change in net income between 2018 and 2019?
{"Income Statement Data: -- Total revenues": {"2019 (1)(2)": 1258294.0, "2018 (3)": 1009780.0, "2017 (4)": 1024191.0, "2016 (5)": 1005701.0, "2015": 1045977.0}, "Income Statement Data: -- Net income": {"2019 (1)(2)": 67062.0, "2018 (3)": 68921.0, "2017 (4)": 5135.0, "2016 (5)": 129535.0, "2015": 85436.0}, "Earnings per share: -- Basic": {"2019 (1)(2)": 0.58, "2018 (3)": 0.59, "2017 (4)": 0.04, "2016 (5)": 1.1, "2015": 0.73}, "Earnings per share: -- Diluted": {"2019 (1)(2)": 0.57, "2018 (3)": 0.59, "2017 (4)": 0.04, "2016 (5)": 1.09, "2015": 0.72}, "Weighted average common shares outstanding: -- Basic": {"2019 (1)(2)": 116175.0, "2018 (3)": 116057.0, "2017 (4)": 118059.0, "2016 (5)": 117533.0, "2015": 117465.0}, "Weighted average common shares outstanding: -- Diluted": {"2019 (1)(2)": 118571.0, "2018 (3)": 117632.0, "2017 (4)": 119444.0, "2016 (5)": 118847.0, "2015": 118919.0}}
net_income_2019 = df["Income Statement Data: -- Net income"]["2019 (1)(2)"]
net_income_2018 = df["Income Statement Data: -- Net income"]["2018 (3)"]
answer = (net_income_2019 - net_income_2018) / net_income_2018 * 100.0