Among the 61 countries analysed, only five countries use a single-memberconstituency system requiring a plural or an absolute majority for the only chamber or lower chamber of parliament, i.e. Azerbaijan, Belarus, France, United Kingdom and the United States of America. Azerbaijan uses a plurality (or first-past-the-post) system with 125 single-member constituencies for electing the members of parliament. Belarus uses the same system for the House of Representatives, with 110 single-member constituencies. For the elections to the National Assembly of France, there is a majority system with two rounds within 577 single-member constituencies. The United Kingdom elects 650 members of the House of Commons in 650 single-member constituencies in a plurality system. The United States of America elect 435 members of the House of Representatives in 435 single-member constituencies under a plurality system as well. In summary, apart from France which applies a majority system, all countries using singlemember-constituency systems use plurality systems.