Loan-level data from single-family mortgage-backed securities issued by Fannie Mae and Freddie Mac show subtle signs of credit easing so far in 2015, according to a new Inside The GSEs analysis.Average credit scores and debt-to-income ratios, when loans are sorted by purpose, have bounced around from month to month without showing much indication that lenders are making loans to riskier borrowers. The average credit score for purchase mortgages securitized in January, for example, was 750.5. In October, it was 751.7, and the average for the first 10 months of the year was 752.0. Refi loans generally have lower credit scores; the average so far for 2015 is 745.3, but there is some evidence that the credit box has been expanding in...