Every passenger ship safety certificate, cargo ship safety equipment certificate or local general safety certificate shall state the maximum number of persons which the vessel is fit to carry, distinguishing, if necessary, between the respective numbers to be carried on the deck and in the cabins and in different parts of the deck and cabins, and any conditions and variations to which those numbers shall be subject, according to the time of the year, the nature of the voyage, the cargo carried, or other circumstances, as the case requires.