Apportionment

the act of apportioning.

the determination of the number of members of the U.S. House of Representatives according to the proportion of the population of each state to the total population of the U.S.

the apportioning of members of any other legislative body.

noun

partition , division , allocation , appropriation , portion , admeasurement , assignment , dispensation , allotment , allowance , dividend , measure , part , share