What was the change in the Discount rate between 2018 and 2019?
{"Projected benefit obligation at the beginning of the year": {"2019": 61.0, "2018": 50.4}, "Additions due to acquisition of Microsemi": {"2019": 9.8, "2018": "\u2014"}, "Service cost": {"2019": 1.5, "2018": 2.2}, "Interest cost": {"2019": 1.1, "2018": 1.0}, "Actuarial losses": {"2019": 6.0, "2018": 0.7}, "Benefits paid": {"2019": -0.9, "2018": -0.8}, "Foreign currency exchange rate changes": {"2019": -5.8, "2018": 7.5}, "Projected benefit obligation at the end of the year": {"2019": 72.7, "2018": 61.0}, "Accumulated benefit obligation at the end of the year": {"2019": 66.7, "2018": 55.5}, "Weighted average assumptions -- Discount rate": {"2019": 1.41, "2018": 1.73}, "Weighted average assumptions -- Rate of compensation increase": {"2019": 2.79, "2018": 2.91}}
discount_rate_2019 = df["Weighted average assumptions -- Discount rate"]["2019"]
discount_rate_2018 = df["Weighted average assumptions -- Discount rate"]["2018"]
answer = discount_rate_2019 - discount_rate_2018