What was the increase / (decrease) in Income before income tax expense from 2019 to 2018?
{"Statutory income tax rate": {"2019": 26.7, "2018": 26.7}, "Income before income tax expense": {"2019": 2755, "2018": 2817}, "Computed income tax expense": {"2019": 736, "2018": 752}, "Increase (decrease) in income tax expense resulting from: -- Non-deductible stock-based compensation": {"2019": "\u2013", "2018": 5}, "Increase (decrease) in income tax expense resulting from: -- Non-deductible portion of equity losses": {"2019": 7, "2018": 1}, "Increase (decrease) in income tax expense resulting from: -- Income tax adjustment, legislative tax change": {"2019": -23, "2018": "-"}, "Increase (decrease) in income tax expense resulting from: -- Non-taxable portion of capital gains": {"2019": -2, "2018": -9}, "Increase (decrease) in income tax expense resulting from: -- Other items": {"2019": -6, "2018": 9}, "Increase (decrease) in income tax expense resulting from: -- Total income tax expense": {"2019": 712, "2018": 758}, "Increase (decrease) in income tax expense resulting from: -- Effective income tax rate": {"2019": 25.8, "2018": 26.9}, "Increase (decrease) in income tax expense resulting from: -- Cash income taxes paid": {"2019": 400, "2018": 370}}
income_2019 = df["Income before income tax expense"]["2019"]
income_2018 = df["Income before income tax expense"]["2018"]
answer = income_2019 - income_2018