What was the percentage change in the fair value of plan assets between 2018 and 2019?
{"Projected benefit obligation": {"2019": 174690, "2018": 161104}, "Accumulated benefit obligation": {"2019": 161729, "2018": 152380}, "Fair value of plan assets": {"2019": 158101, "2018": 151715}}
fair_value_2019 = df["Fair value of plan assets"]["2019"]
fair_value_2018 = df["Fair value of plan assets"]["2018"]
answer = (fair_value_2019 - fair_value_2018) / fair_value_2018 * 100.0