What is the percentage change in the exempt property rental profits and revaluations from 2018 to 2019?
{"Loss before tax, joint ventures and associates": {"2019": -1856.8, "2018": -1139.6}, "Loss before tax multiplied by the standard rate of tax in the UK of 19% (2018: 19%)": {"2019": -352.8, "2018": -216.6}, "Exempt property rental profits and revaluations": {"2019": 307.0, "2018": 214.9}, "": {"2019": -45.8, "2018": -1.7}, "Tax on shortfall of minimum PID": {"2019": 22.1, "2018": "\u2013"}, "Additions and disposals of property and investments": {"2019": 7.1, "2018": 0.3}, "Non-deductible and other items": {"2019": 3.4, "2018": 3.4}, "Overseas taxation": {"2019": -3.4, "2018": -0.4}, "Unprovided deferred tax1": {"2019": 22.4, "2018": -7.3}, "Total tax expense/(credit)": {"2019": 5.8, "2018": -5.7}}
exempt_property_rental_profits_and_revaluations_2019 = df["Exempt property rental profits and revaluations"]["2019"]
exempt_property_rental_profits_and_revaluations_2018 = df["Exempt property rental profits and revaluations"]["2018"]
answer = ( exempt_property_rental_profits_and_revaluations_2019 - exempt_property_rental_profits_and_revaluations_2018 ) / exempt_property_rental_profits_and_revaluations_2018 * 100.0