1. A method for aggregating and reporting data from a plurality of data sources in a contact center, the method comprising: maintaining by a computer device the data for a sliding interval comprising a plurality of panes, the data for each of the panes comprising a separate field for an ongoing component for ongoing events and a separate field for a completed component for completed events; updating by the computer device the data for the sliding interval based on updates for the sliding interval received from one or more of the data sources; and reporting by the computer device an aggregation of the ongoing and completed components of the data sources for the sliding interval to a client in accordance with an expiring of one of the panes.