Canada sets the demand for a duplex outlet at 1 amp so 12 for a 15 or 20 amp circuit as the maximum number is 12 unless the load is fixed and known. For example you use plugs and receptacles for lighting Each luminaire is .25 amps so if each duplex is loade to .5 amps you could go to 24 duplex outlets on a 15 amp circuit loaded to %80.
