Please read this before proceeding.

To view this interactive map, most users will require a special piece of software, compatible with the emerging SVG graphic format. We recommend the free SVG Viewer v3 by Adobe, available for Windows, Mac, and other operating systems.

Users of Windows NT, 2000 or XP may require the assistance of their systems administrators to install Adobe SVG Viewer. This chart is known not to be compatible with Netscape v4.7 on Windows NT.

SVG (Scalable Vector Graphic) is a relatively new data format, which combines the benefits of Flash with the flexibility of XML. SVG is recommended as a 'Web standard' by the World Wide Web Consortium.

The Office for National Statistics is keen to receive feedback on this interactive chart, and the use of the SVG format. If you have any comments, please email svg@ons.gov.uk.