What is the increase / (decrease) in the current assets from 2018 to 2019?
{"": {"2019": "", "2018": "(in thousands)", "2017": ""}, "Current assets(*)": {"2019": 351597, "2018": 339562, "2017": 362477}, "Current liabilities": {"2019": 318672, "2018": 239327, "2017": 316101}, "Working capital": {"2019": 32925, "2018": 100235, "2017": 46376}}
current_assets_2019 = df["Current assets(*)"]["2019"]
current_assets_2018 = df["Current assets(*)"]["2018"]
answer = current_assets_2019 - current_assets_2018