Census returns contain the official enumeration of the Canadian population, making them one of the most useful sources for genealogical research. While census returns prior to 1851 are rarely complete for any geographical area, those between 1851 and 1916 hold a wealth of information concerning Canadian residents, such as age, occupation, ethnic origin, religion and country or province of birth. Census returns after 1916 are closed under the Statistics Act and the Act to Amend the Statistics Act. Legislation does not permit the disclosure of personal information until 92 years has passed since the time of enumeration. Agricultural censuses form part of the collection as do materials that assist users in consulting censuses, such as electoral maps, city directories, and Statistics Canada publications.