What is the percentage difference of the U.S. and international net periodic benefit cost included in cost of sales for year 2017 to year 2019?
{"Net periodic benefit (income) cost: -- U.S. and international net periodic benefit cost included in cost of sales(1)": {"2019": 1.1, "2018": 0.8, "2017": 1.4}, "Net periodic benefit (income) cost: -- U.S. and international net periodic benefit cost included in selling, general and administrative expenses": {"2019": 2.8, "2018": 3.5, "2017": 5.6}, "Net periodic benefit (income) cost: -- U.S. and international net periodic benefit (income) included in other (income) expense": {"2019": -4.4, "2018": -8.4, "2017": -6.0}, "Net periodic benefit (income) cost: -- Total benefit (income) cost": {"2019": -0.5, "2018": -4.1, "2017": 1.0}}
us_benefit_2019 = df["Net periodic benefit (income) cost: -- U.S. and international net periodic benefit cost included in cost of sales(1)"]["2019"]
us_benefit_2017 = df["Net periodic benefit (income) cost: -- U.S. and international net periodic benefit cost included in cost of sales(1)"]["2017"]
answer = (us_benefit_2019 - us_benefit_2017) / us_benefit_2017 * 100.0