The flow of new mortgages delivered to Fannie Mae and Freddie Mac declined by 19.9 percent from the third to the fourth quarter of 2015, and a larger share of them came from third-party originators, according to a new Inside Mortgage Trends analysis of mortgage-backed securities data. The two government-sponsored enterprises securitized $179.01 billion of single-family mortgages during the fourth quarter of last year. Although the biggest factor ... [Includes two data charts]