Yearly stock estimates of overseas Filipinos which CFO started in 1994, is prepared on the basis of both primary sources and secondary sources of data. The primary sources are the registration data of emigrants and other clientele of the Commission on Filipinos Overseas (for permanent migrants), overseas employment data from the Philippine Overseas Employment Administration (for temporary migrants), and consolidated reports (including irregular migrants) from the more than eighty Foreign Service posts of the Department of Foreign Affairs. Secondary sources are census and other data from various host countries, which serve as reference or comparators in the estimations.