What was the change in additions from 2018 to 2019?
{"As of January 1,": {"2018": 20800, "2019": 20713}, "Additions": {"2018": 136, "2019": 158}, "Share of profit of associates": {"2018": 1800, "2019": 1627}, "Dividend declared": {"2018": -2023, "2019": -878}, "As of December 31,": {"2018": 20713, "2019": 21620}}
additions_2019 = df["Additions"]["2019"]
additions_2018 = df["Additions"]["2018"]
answer = additions_2019 - additions_2018