What was the increase / (decrease) in the investment in Equity Securities from 2018 to 2019?
{"Cash and cash equivalents": {"2019": 1, "2018": 2}, "Equity securities": {"2019": 24, "2018": 27}, "Government debt securities": {"2019": 12, "2018": 3}, "Corporate debt securities": {"2019": 16, "2018": 26}, "Investments in funds(a)": {"2019": 21, "2018": 17}, "Real estate": {"2019": 2, "2018": 3}, "Other (mainly insurance assets  contracts and reserves)": {"2019": 24, "2018": 22}, "Total": {"2019": 100, "2018": 100}}
equity_securities_2019 = df["Equity securities"]["2019"]
equity_securities_2018 = df["Equity securities"]["2018"]
answer = equity_securities_2019 - equity_securities_2018