A standard selection rule’s count describes the number of records that matched the standard selection rule’s criteria at the point in time when the count was last refreshed.
The date and time at which the count was generated is display immediately below the count itself.
When you open a selection rule, if a count had been generated previously, the most recently-generated version thereof is displayed automatically at the panel. If the count is more than an hour old, an information icon is shown. A tooltip is shown on hovering over a previously-generated count:
