Freddie Mac reported this week that its total mortgage portfolio increased at an annualized rate of 17.7 percent in February compared to a 16.1 percent gain in January. The portfolio balance at the end of the period was $ 2.818 trillion compared to $ 2.777 trillion the prior month and $ 2.350 trillion a year earlier. Purchases and Issuances totaled $ 116.362 billion, and Sales were ($ 1.174) billion. The January numbers were $ 120.128 billion and ($ .588) billion, respectively. Single-family refinance loan purchase and guarantee volume was $ 85.0 billion in February compared to $ 84.56 billion in January, representing a 77 percent share of total single-family mortgage portfolio purchases and issuances, up from 73 percent the previous month.