Castle Company provides estimates for its uncollectible accounts. The allowance for uncollectible accounts had a credit balance of $17,680 at the beginning of 2021 and a $23,210 credit balance at the end of 2021 (after adjusting entries). If the direct write-off method had been used to account for uncollectible accounts (bad debt expense equals actual write-offs), the income statement for 2021 would have included bad debt expense of $17,900 and revenue of $3,000 from the collection of previously written off bad debts. Required: Determine bad debt expense for 2021 according to the allowance method. Bad debt expense for the year 2021