What was the change in cash equivalents between 2018 and 2019?
{"Cash": {"2019": 8.2, "2018": 9.5}, "Cash equivalents": {"2019": 7.2, "2018": 10.8}, "Cash and cash equivalents": {"2019": 15.4, "2018": 20.3}}
cash_equivalents_2019 = df["Cash equivalents"]["2019"]
cash_equivalents_2018 = df["Cash equivalents"]["2018"]
answer = cash_equivalents_2019 - cash_equivalents_2018