What was the percentage change in Cash-settled transactions in 2019 from 2018?
{"": {"Year-ended 31 March 2019": "$M", "Year-ended 31 March 2018": "$M"}, "Cash-settled transactions": {"Year-ended 31 March 2019": 1.9, "Year-ended 31 March 2018": 2.7}, "Equity-settled transactions": {"Year-ended 31 March 2019": 35.0, "Year-ended 31 March 2018": 39.6}, "Total share-based payment expense": {"Year-ended 31 March 2019": 36.9, "Year-ended 31 March 2018": 42.3}}
cash_settled_2019 = df["Cash-settled transactions"]["Year-ended 31 March 2019"]
cash_settled_2018 = df["Cash-settled transactions"]["Year-ended 31 March 2018"]
answer = (cash_settled_2019 - cash_settled_2018) / cash_settled_2018 * 100.0