ยง 4530. Certificate of population. (a) Prima facie evidence. A certificate of the officer in charge of the census of the United States, attested by the United States secretary of commerce, giving the result of the census is, except as hereinafter provided, prima facie evidence of such result. (b) Conclusive evidence. Where the population of the state or a subdivision, or a portion of a subdivision of the state is required to be determined according to the federal or state census or enumeration last preceding a particular time, a certificate of the officer in charge of the census of the United States, attested by the United States secretary of commerce, as to such population as shown by such federal census, or a certificate of the secretary of state as to such population as shown by such state enumeration, is conclusive evidence of such population.