Mortgage sellers doing business with Fannie Mae and Freddie Mac saw a sharp decline in repurchase activity in the second quarter of 2015 as the buyback focus continued to shift toward more recent production. The two government-sponsored enterprises reported a total of $436.3 million in mortgage repurchases during the second quarter, down 11.2 percent from the previous period. It was the lowest quarterly buyback number since ... [Includes two data charts]