Beginning 2010Q1: Level from Fannie Mae 10-K or 10-Q, table Composition of Mortgage Credit Book of Business, sum of columns Multifamily Conventional and Multifamily Government for rows Fannie Mae MBS and Unconsolidated Fannie Mae MBS Unadjusted flow is the change in the level; data for the most recent ten years show no significant seasonality. Prior to 2010Q1: Level from FNMA, Monthly Volume Summary, Table 4 Fannie Mae Guaranteed Securities and Mortgage Loans, Total Fannie Mae MBS column End Balance, less 4 percent of "Mortgage-related securities that were consolidated in the balance sheet as loans," located in 10-K or 10-Q, Table 20: Mortgage Portfolio Composition, footnote. Unadjusted flow is the change in the level; data for the most recent ten years show no significant seasonality.
