History of the Census
The term Census refers to any count/enumeration of items that are important to a country, such as housing, agriculture or manufacturing, taken at a particular time. Used on its own, however, it usually refers to a census of population. A Census of Population is a count of people and housing in a country or area at a particular time. Its purpose is to provide a statistical portrait of the country and its population.
Almost every country in the world regularly carries out a census to collect important information about the social and economic situation of the people living in its various regions. A census is the only reliable source of detailed data on small areas or groups within the population.
Censuses, which are generally expensive, extremely labour intensive and time consuming, are taken only at infrequent but usually regular intervals, every ten years in many countries, every 5 years or at irregular intervals in other countries.
In non-census years, the population is estimated with the aid of vital statistics, if these are sufficiently reliable. For instance, the population in a post-censal year equals the population at the last census plus the births, minus the deaths, plus or minus the net migration during the intervening years.