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.

How does SSDC use cookies?

Cookies enable us to identify your device. We use cookies (Google Analytics) to help us improve the performance of our website. Google Analytics collect information about how people use this site for example what pages you visit, how long you are on the site, how you got there and what you click on. We do this to make sure that our website is meeting your needs and understand how we can do it better. However, no personal details are stored and you cannot be identified by the information collected.

How do you disable cookies?

Some people find the idea of a website storing information on their computer or mobile device a bit intrusive. Although this is generally harmless if you don't want to receive cookies, you can modify your browser so that it notifies you when cookies are sent to it or you can refuse cookies altogether. However, if you choose to disable or block cookies from this site, some functions will not work.

If you'd like more comprehensive information on how to modify your cookie preferences and how to do this on a wide variety of desktop browsers, then you may wish to visit