What was the change in accrued interest between 2018 and 2019?
{"Operating lease liabilities": {"2019": 15049, "2018": "$ \u2014"}, "Vendor financed licenses": {"2019": 9667, "2018": 3551}, "Royalties payable": {"2019": 6107, "2018": 11318}, "Accrued interest": {"2019": 9212, "2018": 8407}, "Other": {"2019": 36936, "2018": 38412}, "Total other current liabilities": {"2019": 76971, "2018": 61688}}
accrued_interest_2019 = df["Accrued interest"]["2019"]
accrued_interest_2018 = df["Accrued interest"]["2018"]
answer = accrued_interest_2019 - accrued_interest_2018