What was the change in the Additions based on tax positions related to the current year from 2018 to 2019?
{"Balance at January 1,": {"2019": 2871, "2018": 2355, "2017": 1902}, "Additions based on tax positions related to the current year": {"2019": 149, "2018": 160, "2017": 219}, "Additions for tax positions of prior years": {"2019": 297, "2018": 699, "2017": 756}, "Reductions for tax positions of prior years": {"2019": -300, "2018": -248, "2017": -419}, "Settlements": {"2019": -58, "2018": -40, "2017": -42}, "Lapses of statutes of limitations": {"2019": -89, "2018": -55, "2017": -61}, "Balance at December 31,": {"2019": 2870, "2018": 2871, "2017": 2355}}
additions_2019 = df["Additions based on tax positions related to the current year"]["2019"]
additions_2018 = df["Additions based on tax positions related to the current year"]["2018"]
answer = additions_2019 - additions_2018