During general elections, all of the single-member constituencies (seats) that constitute the UK Parliament are subject to separate, simultaneous contests, between several candidates. While these constituencies span the entire UK geographically, because of the way that the population of the UK is distributed – i. e. the population of England is greater than that of Northern Ireland, Scotland and Wales combined – the 533 MPs from English constituencies represent a majority within the House of Commons. Nevertheless, there are often occasions when the votes of MPs from non-English constituencies have proved to be decisive with regard to England-specific legislation (regarding matters that are devolved outside England). (Examples of this phenomenon since devolution include issues with such as foundation hospitals, top-up fees and runways at Heathrow.) To a limited extent, the Scotland Act 1998 has reduced the potential for non-English MPs to form decisive regional blocs – that is, Section 81 of the Act abolished the previous system of apportionment, under which Scottish constituencies required a smaller electoral quota and Scotland was over-represented, relative to the other components of the UK; England now provides more MPs per capita than Scotland.