What is the change in the allocation of equities from 2018 to 2019?
{"Fixed income": {"2019": 40, "2018": 40}, "Equities": {"2019": 55, "2018": 55}, "Other": {"2019": 5, "2018": 5}, "Total": {"2019": 100, "2018": 100}}
equities_2019 = df["Equities"]["2019"]
equities_2018 = df["Equities"]["2018"]
answer = equities_2019 - equities_2018