Methodology as per CoreLogic: The foreclosure inventory represents the number and ratio of homes that have been placed into the process of foreclosure by the mortgage servicer. Mortgage servicers start the foreclosure process when the mortgage reaches a specific level of serious delinquency as dictated by the investor for the mortgage loan ... The foreclosure inventory is measured only against homes that have an outstanding mortgage. Homes with no mortgage liens can never be in foreclosure and are therefore excluded from the analysis.
For further information, go to www.corelogic.com