Freddie Mac officials are moving to bring the same level of transparency available for their fixed-rate MBS to their adjustable-rate paper, as the share of ARM mortgages continues to grow. In a statement released late last week, the government-sponsored enterprise said it will provide investors with five new data fields for its ARM PCs and ARM Giant PCs, as well as its interest-only FRM and ARM securities. The new data will be available in September,…