Where were the most slaves in ancient rome, ancient egypt or in ancient babylon, and why?

The largest number of slaves over a long period of time was possessed by Rome. Reasons: the structure of Roman society, constant wars and the seizure of vast territories and population, the natural growth of slaves (they multiplied). Babylon does not claim to be the first because of the possession of much smaller territories. The second place should be taken by ancient Greece due to the aggressive campaigns of Alexander the Great, but already at that time democracy was emerging in Greek society. The second place belongs to Egypt. But he was subdued and plundered by the Romans.