Census

The complete enumeration of a population or groups at a point in time with respect to well-defined characteristics: for example, population,production, traffic on particular roads. In some connection the term is associated with the data collected rather than the extent of the collection so that the term sample census has a distinct meaning. The partial enumeration resulting from a failure to cover the whole population, as distinct from a designed sample enquiry, may be referred to as an "incomplete census." (DOE5)