In the three months following the Reserve Bank's May cash rate cut, bank retail deposits increased by 1.2 per cent - an annualised rate of 4.8 per cent. Over the past couple of years, banks have been used to seeing their deposit books grow at eight or nine per cent a year.Banking statistics released by the Australian Prudential Regulation Authority on Friday show total bank retail bank deposits increasing by just 0.2 per cent in July - an annualised rate of 2.4 per cent.Banks are yet to see the impact of the August cash rate cut on deposits but the trend appears to be downwards.Among the big banks, Westpac's deposit book grew by 1.5 per cent over the three months to July, Commonwealth Bank's by 1.3 per cent, ANZ's by one per cent and National Australia Bank's by 0.2 per cent.Banks with big inflows included ME Bank, whose deposit book increased by 14.8 per cent over the three months, Macquarie Bank (up 9.9 per cent), RaboDirect (up 8.9 per cent), and HSBC (up 4.9 per cent).Citibank suffered a 2.5 per cent net outflow during the three months to July, Bendigo and Adelaide Bank had a 0.5 per cent net outflow, Bank of Queensland had a 0.4 per cent net outflow, and Arab Bank had a 5.5 per cent net outflow.