What was the change in the amount of assets in Thailand between 2018 and 2019?
{"United States": {"2019": 521.1, "2018": 393.3}, "Thailand": {"2019": 209.3, "2018": 215.5}, "Various other countries": {"2019": 266.3, "2018": 159.1}, "Total long-lived assets": {"2019": 996.7, "2018": 767.9}}
thailand_2019 = df["Thailand"]["2019"]
thailand_2018 = df["Thailand"]["2018"]
answer = thailand_2019 - thailand_2018