Allowance and irrecoverable debts

At january 20X1,there was an allowance for receivables of 3000$,during the year,1000$ of debts were written off as irrecoverable,and 800$ of debts previously written off were recovered.
At 31 December 20X1, it was decided to adjust the allowance for receivables to 5% of receivables which are 20000$
what is the total receivables expense for the year?
Here:
”during the year” expression means from 1 january 20X1 to 31 december 20X1??
And irrecoverable debt expense of 1000$ belongs to 20X0 fnancial year? but not 20X1??
Please explain