Interest rates on adjustable-rate mortgages fell to their lowest level ever early this year, but consumers continue to prefer fixed-rate products. Freddie Mac reported that the average initial rate for one-year ARMs offered in early January was just 2.56 percent, the lowest ever recorded in its 29-year-old survey. Fewer than half the participating lenders offer one-year ARMs, but initial rates on the more common three-year and five-year hybrids were 2.72 percent and ... [Includes one data chart]