How much is the percentage change in the projected benefit obligations from 2018 to 2019?
{"Plans with accumulated benefit obligations in excess of plan assets: -- Accumulated benefit obligations": {"2019": 75.6, "2018": 130.7}, "Plans with accumulated benefit obligations in excess of plan assets: -- Plan assets": {"2019": 70.0, "2018": 112.1}, "Plans with projected benefit obligations in excess of plan assets: -- Projected benefit obligations": {"2019": 91.6, "2018": 158.1}, "Plans with projected benefit obligations in excess of plan assets: -- Plan assets": {"2019": 80.8, "2018": 121.1}}
projected_benefit_obligations_2019 = df["Plans with projected benefit obligations in excess of plan assets: -- Projected benefit obligations"]["2019"]
projected_benefit_obligations_2018 = df["Plans with projected benefit obligations in excess of plan assets: -- Projected benefit obligations"]["2018"]
answer = ( ( projected_benefit_obligations_2019 - projected_benefit_obligations_2018 ) / projected_benefit_obligations_2018 ) * 100.0