What was the change in additions between 2018 and 2019?
{"As of January 1": {"2019": 20000, "2018": 1177489}, "Additions": {"2019": 372849, "2018": 118942}, "Transfer to vessels and equipment, net (note 16)": {"2019": "\u2014", "2018": -1296431}, "Transfer from vessels and equipment, net (note 16)": {"2019": "\u2014", "2018": 20000}, "Transfer from other non-current assets (note 17)": {"2019": 31048, "2018": "\u2014"}, "Interest costs capitalized": {"2019": 10351, "2018": "\u2014"}, "As of December 31": {"2019": 434248, "2018": 20000}}
additions_2019 = df["Additions"]["2019"]
additions_2018 = df["Additions"]["2018"]
answer = additions_2019 - additions_2018