What was the change in the carrying amount as of 31 December from 2018 to 2019?
{"Cost: -- Balance as of 1 January": {"2019": 5.8, "2018": 3.6, "2017": 2.7}, "Cost: -- Adjustment on transition to IFRS 16": {"2019": 0.3, "2018": "-", "2017": "-"}, "Cost: -- Additions": {"2019": 2.2, "2018": 2.2, "2017": 1.0}, "Cost: -- Disposals": {"2019": -0.2, "2018": "-", "2017": -0.1}, "Cost: -- Balance as of 31 December": {"2019": 8.1, "2018": 5.8, "2017": 3.6}, "Depreciation: -- Balance as of 1 January": {"2019": 2.8, "2018": 1.7, "2017": 0.9}, "Depreciation: -- Disposals": {"2019": "-", "2018": "-", "2017": -0.1}, "Depreciation: -- Depreciation for the year": {"2019": 1.0, "2018": 1.1, "2017": 0.9}, "Depreciation: -- Balance as of 31 December": {"2019": 3.8, "2018": 2.8, "2017": 1.7}, "Depreciation: -- Carrying amount as of 31 December": {"2019": 4.3, "2018": 3.0, "2017": 1.9}}
carrying_amount_2019 = df["Depreciation: -- Carrying amount as of 31 December"]["2019"]
carrying_amount_2018 = df["Depreciation: -- Carrying amount as of 31 December"]["2018"]
answer = carrying_amount_2019 - carrying_amount_2018