The Encyclopedia Americana says that in the fourth century B.C.E., slaves in Athens and two other Greek cities outnumbered the free population by about 4 to 1.
The Encyclopedia Americana ütleb, et neljandal sajandil e.m.a. oli Ateena ja kahe teise Kreeka linna orjade arv vabade elanike arvust ligi 4 korda suurem.