Use of cookies on this site

We use cookies to help us improve our website. We collect data in a way that doesn't identify you and data isn't shared with anyone else.

The table below gives details of all cookies we set.

This website will function fully for you if you do not wish to accept our persistent cookies.

Detailed list of cookies set on your computer.
 Cookie and name  Expires Purpose 
ASP.NET_SessionID When you close the browser Identifies your session on the web server.
Google Analytics _ga 2 years Distinguishes users.
Google Analytics _ _utma 2 years from set / update Distinguishes users and sessions. The cookie is created when the javascript library executes and no existing _ _utma cookies exists. The cookie is updated every time data is sent to Google Analytics.
Google Analytics _ _utmb 30 minutes from set / update Determines new sessions/visits. The cookie is created when the javascript library executes and no existing _ _utmb cookies exists. The cookie is updated every time data is sent to Google Analytics.
Google Analytics _ _utmc When you close the browser Not used in ga.js. Set for interoperability with urchin.js. Historically, this cookie operated in conjunction with the _ _utmb cookie to determine whether the user was in a new session/visit.
Google Analytics _ _utmt 10 minutes Throttles request rate
Google Analytics _ _utmz 6 months from set /update Stores the traffic source or campaign that explains how the user reached your site. The cookie is created when the javascript library executes and is updated every time data is sent to Google Analytics.
Google Analytics _gat 1 minute Throttles request rate. If Google Analytics is deployed via Google Tag Manager, this cookie will be named _dc_gtm_<property- id>.
Google Analytics _ gid 24 hours Used to distinguish users
Siteimprove nmstat 1000 days Collects statistics about site usage.