census

n. counting and surveying of the population for official purposes

A census is the process of obtaining information about every member of a population (not necessarily a human population). The term is mostly used in connection with national 'population and housing censuses' (to be taken every 10 years according to United Nations recommendations); agriculture censuses (all agriculture units) and business censuses (all enterprises).
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n. census, counting and surveying of the population for official purposes

(n.)
An official registration of the number of the people, the value of their estates, and other general statistics of a country.
  

(n.)
A numbering of the people, and valuation of their estate, for the purpose of imposing taxes, etc.; -- usually made once in five years.
  

the collection of data from all possible sources in a population.