1. A computer-implemented method for providing an automated value estimate of a property as of a previous time period, the computer-implemented method comprising the steps performed by a computer of: determining historical valuation data reflecting automated value estimates of properties, the automated value estimates corresponding to values of the properties during a plurality of previous time periods; storing the historical valuation data in a database; receiving a request for an automated value estimate of a property as of a specified one of the previous time periods, the request identifying the property and the specified one of the previous time periods; searching the database for the historical valuation data of the property identified by the request; retrieving the historical valuation data from the database reflecting the automated value estimate of the property during the specified one of the previous time periods; and providing, in response to the request, the automated value estimate of the property as of the specified one of the previous time periods.