What is the increase / (decrease) in Net Income from 2018 to 2019?
{"Revenue": {"2019": 22104, "2018": 28185, "% Change": -22}, "Cost of Sales": {"2019": -15825, "2018": -21074, "% Change": 25}, "Gross profit": {"2019": 6279, "2018": 7111, "% Change": -12}, "as percentage of revenue": {"2019": 28, "2018": 25, "% Change": ""}, "Research and development expenses": {"2019": -2362, "2018": -2788, "% Change": 15}, "Selling and general administrative expenses": {"2019": -3979, "2018": -3767, "% Change": -6}, "Other operating income (expenses), net": {"2019": 9469, "2018": 1, "% Change": "n / a"}, "Financial income, net thereof Income from investments, net 3,754 (prior year 5,381)": {"2019": 3188, "2018": 4643, "% Change": -31}, "Income from business activity": {"2019": 12596, "2018": 5199, "% Change": 142}, "Income taxes": {"2019": -1377, "2018": -653, "% Change": -111}, "Net income": {"2019": 11219, "2018": 4547, "% Change": 147}, "Profit carried forward": {"2019": 170, "2018": 134, "% Change": 27}, "Allocation to other retained earnings": {"2019": -6005, "2018": -1451, "% Change": -200}, "Unappropriated net income": {"2019": 5384, "2018": 3230, "% Change": 67}}
net_income_2019 = df["Net income"]["2019"]
net_income_2018 = df["Net income"]["2018"]
answer = net_income_2019 - net_income_2018