If you've noticed a drop-off in the number of citations found since your last report, it could be because some citations were discovered that are no longer live — i.e. we could not access the page because either the whole site, or that specific page, no longer exists.
We carry out a review and cleanup of citations every 30 days to ensure that our Citation Tracker reports are both up-to-date and accurate, as well as accessing each of the citations in your report to ensure they are still live. Any sites that return a '404' or '410' error (which indicates that this particular page is no longer accessible on the web) are then removed.
When we identify and remove these 'dead' citations, a handy notification is shown at the top of your Citation Tracker report telling you how many citations were removed (see below in the red box for an example) — this notification will remain in place until the next time your report is run.