What was the percentage change in Service Cost from 2018 to 2019?
{"Projected benefit obligation: -- Beginning of year": {"2019": 9256, "2018": 6177}, "Projected benefit obligation: -- Service cost": {"2019": 41, "2018": 39}, "Projected benefit obligation: -- Interest cost": {"2019": 347, "2018": 196}, "Projected benefit obligation: -- Actuarial loss": {"2019": 717, "2018": 25}, "Projected benefit obligation: -- Benefits paid": {"2019": -1358, "2018": -889}, "Projected benefit obligation: -- Special termination benefits": {"2019": "\u2014", "2018": 3708}, "Projected benefit obligation: -- End of year": {"2019": 9003, "2018": 9256}, "Fair value of plan assets: -- Beginning of year": {"2019": "\u2014", "2018": "\u2014"}, "Fair value of plan assets: -- Company contributions": {"2019": 1358, "2018": 889}, "Fair value of plan assets: -- Benefits paid": {"2019": -1358, "2018": -889}, "Fair value of plan assets: -- End of year": {"2019": "\u2014", "2018": "\u2014"}, "Fair value of plan assets: -- Funded status": {"2019": -9003, "2018": -9256}}
service_cost_2019 = df["Projected benefit obligation: -- Service cost"]["2019"]
service_cost_2018 = df["Projected benefit obligation: -- Service cost"]["2018"]
answer = ( service_cost_2019 - service_cost_2018 ) / service_cost_2018 * 100.0