What was the percentage change in the fair value of plan assets at end of period between 2018 and 2019?
{"Change in projected benefit obligation: -- Projected benefit obligation at beginning of period": {"2019": 37245, "2018": 34893}, "Change in projected benefit obligation: -- Service cost": {"2019": 1471, "2018": 1193}, "Change in projected benefit obligation: -- Interest cost": {"2019": 634, "2018": 727}, "Change in projected benefit obligation: -- Actuarial loss - experience": {"2019": 453, "2018": 38}, "Change in projected benefit obligation: -- Actuarial loss - assumptions": {"2019": 5091, "2018": 2139}, "Change in projected benefit obligation: -- Benefit payments": {"2019": -166, "2018": -138}, "Change in projected benefit obligation: -- Effects of foreign currency exchange rate changes": {"2019": -826, "2018": -1607}, "Change in projected benefit obligation: -- Projected benefit obligation at end of period": {"2019": 43902, "2018": 37245}, "Change in plan assets: -- Fair value of plan assets at beginning of period": {"2019": 24159, "2018": 26624}, "Change in plan assets: -- Actual gain (loss) on plan assets": {"2019": 4392, "2018": -2024}, "Change in plan assets: -- Contributions": {"2019": "\u2014", "2018": 688}, "Change in plan assets: -- Effects of foreign currency exchange rate changes": {"2019": -535, "2018": -1129}, "Change in plan assets: -- Fair value of plan assets at end of period": {"2019": 28016, "2018": 24159}, "Change in plan assets: -- Unfunded status at end of period": {"2019": -15886, "2018": -13086}}
fair_value_2019 = df["Change in plan assets: -- Fair value of plan assets at end of period"]["2019"]
fair_value_2018 = df["Change in plan assets: -- Fair value of plan assets at beginning of period"]["2019"]
answer = (fair_value_2019 - fair_value_2018) / fair_value_2018 * 100.0