▁also ▁live ▁somewhere ▁else , ▁to ▁allow ▁these ▁estimates ▁to ▁be ▁made . ▁ ▁Other ▁estimates ▁are ▁concerned ▁with ▁estim ating ▁population ▁on ▁a ▁particular ▁date ▁that ▁is ▁different ▁from ▁the ▁census ▁date , ▁for ▁example ▁the ▁middle ▁or ▁end ▁of ▁a ▁calendar ▁or ▁financial ▁year . ▁These ▁estimates ▁often ▁use ▁birth ▁and ▁death ▁records ▁and ▁migration ▁data ▁to ▁adjust ▁census ▁counts ▁for ▁the ▁changes ▁that ▁have ▁happened ▁since ▁the ▁census . ▁ ▁Population ▁pro jections ▁are ▁produced ▁in ▁advance ▁of ▁the ▁date ▁they ▁are ▁for . ▁They ▁use ▁time ▁series ▁analysis ▁of ▁existing ▁census ▁data ▁and ▁other ▁sources ▁of ▁population ▁information ▁to ▁forec ast ▁the ▁size ▁of ▁future ▁populations . ▁Because ▁there ▁are ▁unknown ▁factors ▁that ▁may ▁affect ▁future ▁population ▁changes , ▁population ▁pro jections ▁often ▁incorpor ate ▁high ▁and ▁low ▁as ▁well ▁as ▁expected ▁values ▁for ▁future ▁populations . ▁Population ▁pro jections ▁are ▁often ▁re comput ed ▁after ▁a ▁census ▁has ▁been ▁conducted . ▁It ▁depends ▁on ▁how ▁the ▁area ▁is ▁adjust ed ▁in ▁a ▁particular ▁dem arc ation . ▁ ▁History ▁While ▁many ▁cens uses ▁were ▁conducted ▁in ▁anti qu ity , ▁there ▁are ▁few ▁population ▁statistics ▁that ▁surv ive . ▁One ▁example ▁though ▁can ▁be ▁found ▁in ▁the ▁Bible , ▁in ▁chapter ▁ 1 ▁of ▁the ▁Book ▁of ▁Num bers . ▁Not ▁only ▁are ▁the ▁statistics ▁given , ▁but ▁the ▁method ▁used ▁to ▁compile ▁those ▁statistics ▁is ▁also ▁described . ▁In ▁modern - day ▁terms , ▁this ▁metadata ▁about ▁the ▁census ▁is ▁probably ▁of ▁as ▁much ▁value ▁as ▁the