What was the total percentage change in the Net periodic benefit cost between 2017 and 2019?
{"Service cost": {"2019": 1437, "2018": 1063, "2017": 1068}, "Interest cost": {"2019": 3715, "2018": 3807, "2017": 2942}, "Expected long-term return on plan assets": {"2019": -5291, "2018": -5954, "2017": -4206}, "Recognized actuarial loss": {"2019": 741, "2018": 1127, "2017": 1929}, "Amortization of prior service credit": {"2019": -44, "2018": -88, "2017": -138}, "Net settlement loss": {"2019": 634, "2018": 116, "2017": 1472}, "Net periodic benefit cost": {"2019": 1192, "2018": 71, "2017": 3067}}
net_periodic_benefit_cost_2019 = df["Net periodic benefit cost"]["2019"]
net_periodic_benefit_cost_2017 = df["Net periodic benefit cost"]["2017"]
answer = (net_periodic_benefit_cost_2019 - net_periodic_benefit_cost_2017) / net_periodic_benefit_cost_2017 * 100.0