The outstanding supply of Fannie Mae and Freddie Mac single-family servicing contracted slightly during the first quarter of 2015, but that didn’t stop a number of nonbank servicers from continuing to grow.The two GSEs had a total of $4.015 trillion of servicing attached to mortgage-backed securities at the end of March, according to a new Inside The GSEs analysis of MBS disclosures.That was down 0.1 percent from the fourth quarter of last year, although the MBS data usually don’t match aggregate disclosures made by the GSEs themselves and they don’t include non-securitized loans. The top five GSE servicers all saw their portfolios decline in early 2015. The biggest drops in percentage terms were by Chase Home Finance, down...(includes one data chart)