The accrual principle and income

Can anyone help me with this question:
A social club has failed to keep a proper set of accounting records. For the year ended 30 April 20×8 you discover the following information concerning subscription income.

Due for the year ended 30 April 20×8-5500
In advance at 1May 20×7-260
In arrears at 1 May 20×7-1620
In advance at 30 April 20×8-240
In arrears at 30 aril 20×8-nil
How much cash was received during the year in respect of subscriptions ?
May I know what is it meant by” due for the year ended 30 April 20×8″, is it accrued income ?