Year-end level from SOI Bulletin, annual article on Partnership Returns, table Balance Sheet, by Profit Status and Selected Industrial Group, 10 percent of line Mortgages, notes, and bonds payable in one year or more (total for all industries except Agriculture, forestry, fishing and hunting, and Finance and insurance). Year-end level also includes FOF estimate for mortgage debt held by sole proprietorships calculated as the ratio of sole proprietorships' income to partnerships' income from the FRB 2003 Survey of Small Business Finance multiplied by the year-end level from SOI Bulletin, annual article on Nonfarm Sole Proprietorships, table Income Statements, by Industrial Sectors, line Business receipts, total (total for all industries except Agriculture, forestry, fishing and hunting, and Finance and insurance). It is estimated that 80 percent of the mortgage debt of sole proprietorships is home mortgage debt. Series is converted to quarterly by linear interpolation. The proportion of home mortgages of noncorporate businesses calculated from the latest SOI date to total home mortgages of all sectors, is used to estimate data for home mortgage liabilities in quarters going forward. Unadjusted flow is the change in the level; data for the most recent ten years show no significant seasonality.