What was the change in Accounts receivable between 2018 and 2019?
{"December 31, -- ": {"2019": 2019, "2018": 2018}, "December 31, -- Accounts receivable": {"2019": 80032, "2018": 52850}, "December 31, -- Allowance for doubtful accounts": {"2019": -2584, "2018": -1425}, "December 31, -- Allowance for product returns": {"2019": -1075, "2018": -1915}, "December 31, -- Accounts receivable, net": {"2019": 76373, "2018": 49510}}
accounts_receivable_2019 = df["December 31, -- Accounts receivable"]["2019"]
accounts_receivable_2018 = df["December 31, -- Accounts receivable"]["2018"]
answer = accounts_receivable_2019 - accounts_receivable_2018