Fannie Mae and Freddie Mac saw a marked decline in refinance business during the second quarter of 2013, but a strengthening housing market helped offset some of the lost volume. The two government-sponsored enterprises securitized $256.0 billion of single-family refinance loans during the second quarter, according to the Inside Mortgage Finance GSE Seller Profile, a quarterly statistical report based on loan-level, mortgage-backed securities disclosures. That was down 13.6 percent from ... [Includes two data charts]