Freddie Mac reported this week that its total mortgage portfolio increased at an annualized rate of 13.2 percent in April compared to a 27.2 percent gain in March. The portfolio balance at the end of the period was $ 2.785 trillion compared to $ 2.927 trillion the prior month and $ 2.434 trillion a year earlier. Purchases and Issuances totaled $ 121.668 billion, and Sales were ($ 1.761) billion. The March numbers were $ 142.465 billion and ($ .785) billion, respectively. Single-family refinance loan purchase and guarantee volume was $ 82.9 billion in April compared to $ 103.3 billion in March, representing a 72 percent share of total single-family mortgage portfolio purchases and issuances, down from 76 percent the previous month.