It's simply the revenues that a bank has accrued during any period, e.g. interest charges, overdraft fees, FX charges for a retail (high street bank). In other words it's the money paid to them by their customers for services.
Don't confuse it with money put on deposit with the bank by its customers.
thanks a lot but now further through researching in banks industry and specifically talking about islamic banking; how can we calculate the sales fugure for such banks?mentioning that they use different and complicated islamic finance tools