What was the change in various guarantees from 2018 to 2019?
{"Various guarantees": {"2018": 451, "2019": 388}, "Other long-term assets": {"2018": 2092, "2019": 1613}, "Cash collaterals on swaps": {"2018": "\u2014", "2019": 22220}, "Total": {"2018": 2543, "2019": 24221}}
various_guarantees_2019 = df["Various guarantees"]["2019"]
various_guarantees_2018 = df["Various guarantees"]["2018"]
answer = various_guarantees_2019 - various_guarantees_2018