What is the percentage change in the sum of cash deposits and derivative financial instrument assets from 2018 to 2019?
{"": {"Group Exposure 31 December 2019": "\u00a3m", "Group Exposure 31 December 2018": "\u00a3m"}, "Counterparty #1": {"Group Exposure 31 December 2019": 64.9, "Group Exposure 31 December 2018": 111.9}, "Counterparty #2": {"Group Exposure 31 December 2019": 43.1, "Group Exposure 31 December 2018": 44.1}, "Counterparty #3": {"Group Exposure 31 December 2019": 38.7, "Group Exposure 31 December 2018": 27.2}, "Counterparty #4": {"Group Exposure 31 December 2019": 26.0, "Group Exposure 31 December 2018": 22.3}, "Counterparty #5": {"Group Exposure 31 December 2019": 20.0, "Group Exposure 31 December 2018": 12.3}, "Sum of five largest exposures": {"Group Exposure 31 December 2019": 192.7, "Group Exposure 31 December 2018": 217.8}, "Sum of cash deposits and derivative financial instrument assets": {"Group Exposure 31 December 2019": 203.5, "Group Exposure 31 December 2018": 244.2}, "Five largest exposures as a percentage of assets at risk": {"Group Exposure 31 December 2019": 95, "Group Exposure 31 December 2018": 89}}
total_assets_2019 = df["Sum of cash deposits and derivative financial instrument assets"]["Group Exposure 31 December 2019"]
total_assets_2018 = df["Sum of cash deposits and derivative financial instrument assets"]["Group Exposure 31 December 2018"]
answer = (total_assets_2019 - total_assets_2018) / total_assets_2018 * 100.0