What is the increase/ (decrease) in Operating income from 2017 to 2019?
{"": {"2019": "", "2018": "(In millions)", "2017": ""}, "Operating income": {"2019": 1203, "2018": 1400, "2017": 1005}, "As percentage of net revenues": {"2019": 12.6, "2018": 14.5, "2017": 12.0}}
operating_income_2019 = df["Operating income"]["2019"]
operating_income_2017 = df["Operating income"]["2017"]
answer = operating_income_2019 - operating_income_2017