What was the change in Amounts written off, net of recoveries between 2018 and 2019?
{"Balance, beginning of period": {"2019": 3912, "2018": 4799, "2017": 3873}, "Provision increase": {"2019": -2561, "2018": -1505, "2017": -2086}, "Amounts written off, net of recoveries": {"2019": 1368, "2018": 2269, "2017": 1305}, "Foreign currency translation adjustments and other": {"2019": -44, "2018": 123, "2017": -145}, "Balance, end of period": {"2019": 5149, "2018": 3912, "2017": 4799}}
amounts_written_off_net_of_recoveries_2019 = df["Amounts written off, net of recoveries"]["2019"]
amounts_written_off_net_of_recoveries_2018 = df["Amounts written off, net of recoveries"]["2018"]
answer = amounts_written_off_net_of_recoveries_2019 - amounts_written_off_net_of_recoveries_2018