Most of the statistics published here are based on the number of work permits issued during the year. As was the case for overall immigration flows, the settlement countries (Australia, Canada, New Zealand and the United States) consider as immigrant workers, persons who have received a permanent immigration permit for employment purposes. In each of these four countries, it is also possible to work on a temporary basis under various programmes (these data are also available in this annex). Data by country of origin are not published for the series.