What was the increase / (decrease) in the cash and cash equivalent from 2018 to 2019?
{"Cash and cash equivalents": {"2019": 12395.0, "2018": 9599.0}, "Working capital (deficit)": {"2019": -67429.0, "2018": -85471.0}, "Current ratio": {"2019": 0.72, "2018": 0.7}}
cash_and_cash_equivalents_2019 = df["Cash and cash equivalents"]["2019"]
cash_and_cash_equivalents_2018 = df["Cash and cash equivalents"]["2018"]
answer = cash_and_cash_equivalents_2019 - cash_and_cash_equivalents_2018