The limitation on this system was simply that the Exchange Bank maintained something close to a 100 per cent ratio between its deposits and its reserves of precious metal and coin. As late as 1760, when its deposits stood at just under 19 million florins, its metallic reserve was over 16 million. A run on the bank was therefore a virtual impossibility, since it had enough cash on hand to satisfy nearly all of its depositors if, for some reason, they all wanted to liquidate their deposits at once. This made the bank secure, no doubt, but it prevented it performing what would now be seen as the defining characteristic of a bank, credit creation.