To enable this service to function, we sometimes place small data files on your computer. These are known as cookies.

To learn more about cookies and how to manage them, visit Or please read on to find out more about how and where we use cookies.

How we use cookies

This service uses essential cookies in some places – we've listed each of them explicitly in a table below with more details about why we use them and how long they will last.

These essential cookies are used for site navigation and session management, and this service may not function correctly without them.

This service may use non-essential cookies in some places. These non-essential cookies are not required to make the service function correctly. If any non-essential cookies are used in this service, you will find them listed below.

If you would like to save your response and complete it another time, we will send you a link so you can return later. Note - we will be unable to do this if you have cookies disabled.

If you don't intend to complete your response, please also click the 'save response' button before you leave as this will prevent other users of this computer from seeing your answers so far. 

Note - we cannot use your answers until you 'Submit your response' on the final page.