What was the change in accrued income in 2019 from 2018?
{"": {"2019": "\u00a3m", "2018": "\u00a3m"}, "Receivables, which are included in trade and other receivables": {"2019": 27.0, "2018": 28.8}, "Accrued income": {"2019": 28.0, "2018": 26.7}, "Deferred income": {"2019": -13.2, "2018": -1.8}}
accrued_income_2019 = df["Accrued income"]["2019"]
accrued_income_2018 = df["Accrued income"]["2018"]
answer = accrued_income_2019 - accrued_income_2018