An exclusive new analysis of 2005 Home Mortgage Disclosure Act filings portrays a mortgage origination business that is markedly more fragmented than is commonly thought. According to HMDA data compiled by Geosegment Systems, a market research firm based in Nashua, NH, the top five mortgage originators last year reported a combined $741.08 billion in volume for 2005, or 25.6 percent of total originations... [Includes 2 page chart]