What is the change in Income taxes at statutory rate between fiscal years 2019 and 2018?
{"": {"2019": "", "2018": "(In thousands) ", "2017": ""}, "Income taxes at statutory rate": {"2019": 13408, "2018": 7132, "2017": 148585}, "Discrete benefit resulting from TCJA ": {"2019": "\u2014", "2018": -37505, "2017": "\u2014"}, "State income taxes": {"2019": 1189, "2018": 1014, "2017": 9038}, "State income tax credits ": {"2019": -2139, "2018": -804, "2017": -606}, "Expiration of state income tax credits ": {"2019": 4121, "2018": 4117, "2017": 642}, "Federal income tax credits ": {"2019": -474, "2018": -460, "2017": -390}, "Federal manufacturers deduction ": {"2019": "\u2014", "2018": "\u2014", "2017": -11527}, "Excess tax benefits ": {"2019": -1388, "2018": -1638, "2017": -3345}, "Nondeductible expenses": {"2019": 1786, "2018": 1890, "2017": 3506}, "Change in valuation allowance ": {"2019": -5380, "2018": -5297, "2017": -1106}, "Other ": {"2019": -570, "2018": 677, "2017": -12}, "Income tax expense (benefit) ": {"2019": 10553, "2018": -30874, "2017": 144785}}
income_tax_2019 = df["Income taxes at statutory rate"]["2019"]
income_tax_2018 = df["Income taxes at statutory rate"]["2018"]
answer = income_tax_2019 - income_tax_2018