Στοιχεία απογραφής Census data Official counts of the population of a place or ethnic group that sometimes include data relating to economic and social conditions. For reports about the social, economic, health, or other characteristics of a population that are generally based on estimates calculated through sampling techniques see [Demographic surveys.] For official public records of births, deaths, marriages, divorces, and other life events see [Vital statistics.] Source: http://id.loc.gov/authorities/genreForms/gf2014026059.html Demographic surveys Vital statistics Census data