What was the percentage change in the Income tax expense, as adjusted (non-GAAP) between 2018 and 2019?
{"Income tax expense, as reported (GAAP)": {"2019": 17.3, "2018": 94.6}, "Accumulated foreign earnings assertion ": {"2019": 10.5, "2018": "\u2014"}, "U.S. Tax Reform": {"2019": -7.0, "2018": -85.9}, "Impact of other special tax items": {"2019": 0.2, "2018": -1.1}, "Impact of valuation allowance release ": {"2019": "\u2014", "2018": 3.6}, "Impact of one-time employee bonus": {"2019": "\u2014", "2018": 0.3}, "Income tax expense, as adjusted (non-GAAP) (1)": {"2019": 21.0, "2018": 11.5}}
income_tax_expense_2019 = df["Income tax expense, as adjusted (non-GAAP) (1)"]["2019"]
income_tax_expense_2018 = df["Income tax expense, as adjusted (non-GAAP) (1)"]["2018"]
answer = (income_tax_expense_2019 - income_tax_expense_2018) / income_tax_expense_2018 * 100.0