What was the percentage change in company contributions between 2018 and 2019?
{"Accumulated benefit obligation": {"2019": 4766, "2018": 4595}, "Change in projected benefit obligation: -- Projected benefit obligation at January 1": {"2019": 4595, "2018": 5134}, "Change in projected benefit obligation: -- Service cost": {"2019": 1, "2018": 2}, "Change in projected benefit obligation: -- Interest cost": {"2019": 170, "2018": 156}, "Change in projected benefit obligation: -- Benefits paid": {"2019": -145, "2018": -157}, "Change in projected benefit obligation: -- Actuarial loss (gain)": {"2019": 145, "2018": -540}, "Change in projected benefit obligation: -- Projected benefit obligation at December 31": {"2019": 4766, "2018": 4595}, "Change in plan assets: -- Assets at fair value at January 1": {"2019": "$\u2014", "2018": "$\u2014"}, "Change in plan assets: -- Actual return on assets": {"2019": "\u2014", "2018": "\u2014"}, "Change in plan assets: -- Company contributions": {"2019": 145, "2018": 157}, "Change in plan assets: -- Benefits paid": {"2019": -145, "2018": -157}, "Change in plan assets: -- Other": {"2019": "\u2014", "2018": "\u2014"}, "Change in plan assets: -- Assets at fair value at December 31": {"2019": "$\u2014", "2018": "$\u2014"}, "Change in plan assets: -- Funded status (plan assets less projected benefit obligations)": {"2019": -4766, "2018": -4595}}
contribution_2019 = df["Change in projected benefit obligation: -- Actuarial loss (gain)"]["2019"]
contribution_2018 = df["Change in plan assets: -- Company contributions"]["2018"]
answer = (contribution_2019 - contribution_2018) / contribution_2018 * 100.0