Of the total balances as of January 31, 2019, what percentage came from convertible debt securities?
{"Balances, January 31, 2018": {"Derivative Contracts": 1.0, "Convertible Debt Securities": 7.8, "Total": 8.8}, "Settlements": {"Derivative Contracts": "\u2014", "Convertible Debt Securities": -3.5, "Total": -3.5}, "(Losses) Gains included in earnings (1)": {"Derivative Contracts": -0.2, "Convertible Debt Securities": 0.5, "Total": 0.3}, "Losses included in OCI": {"Derivative Contracts": "\u2014", "Convertible Debt Securities": -0.4, "Total": -0.4}, "Balances, January 31, 2019": {"Derivative Contracts": 0.8, "Convertible Debt Securities": 4.4, "Total": 5.2}}
total_2019 = df["Balances, January 31, 2019"]["Total"]
convertible_debt_securities_2019 = df["Balances, January 31, 2019"]["Convertible Debt Securities"]
answer = ( convertible_debt_securities_2019 / total_2019 ) * 100.0