What is the percentage change of Net deferred tax assets from 2018 to 2019?
{"Accruals not yet deductible for tax purposes": {"2019": 17.4, "2018": 17.5}, "Net operating loss carryforwards": {"2019": 245.9, "2018": 265.5}, "Foreign, federal and state credits": {"2019": 8.4, "2018": 10.4}, "Employee benefit items": {"2019": 79.5, "2018": 77.0}, "Capitalized expenses": {"2019": 32.2, "2018": 8.9}, "Intangibles": {"2019": 21.8, "2018": "\u2014"}, "Derivatives and other": {"2019": 47.7, "2018": 38.0}, "Sub-total deferred tax assets": {"2019": 452.9, "2018": 417.3}, "Valuation allowance": {"2019": -197.6, "2018": -218.4}, "Total deferred tax assets": {"2019": 255.3, "2018": 198.9}, "Depreciation and amortization": {"2019": -37.0, "2018": -26.8}, "Unremitted foreign earnings": {"2019": -10.0, "2018": "\u2014"}, "Intangible assets": {"2019": "\u2014", "2018": -21.7}, "Other": {"2019": -0.4, "2018": -0.4}, "Total deferred tax liabilities": {"2019": -47.4, "2018": -48.9}, "Net deferred tax assets": {"2019": 207.9, "2018": 150.0}}
net_deferred_tax_assets_2019 = df["Net deferred tax assets"]["2019"]
net_deferred_tax_assets_2018 = df["Net deferred tax assets"]["2018"]
answer = (net_deferred_tax_assets_2019 - net_deferred_tax_assets_2018) / net_deferred_tax_assets_2018 * 100.0