U.S. mortgage rates dropped for a second consecutive week, remaining below 5.0 percent, a key level that may boost home loan demand, a closely watched mortgage survey showed on Thursday.

The lowest mortgage rates in decades and high affordability helped the hard-hit housing market find some footing last year after a three-year slump. Attractive rates bode well for the housing market, which remains highly vulnerable to setbacks and heavily reliant on government intervention.

Interest rates on U.S. 30-year fixed-rate mortgages, the most widely used loan, averaged 4.93 percent for the week ended Feb. 18, down from the previous week's 4.97 percent, according to a survey released by Freddie Mac, the second-largest U.S. mortgage finance company.

That is below the year-ago level of 5.04 percent, but above the record low of 4.71 percent in early December. Freddie Mac started the survey in 1971.

"Mortgage rates eased for the second week, while economic data releases suggest that the housing market may be in a slow state of recovery," Freddie Mac vice president and chief economist, said in a statement.

Mortgage rates are linked to yields on Treasuries and yields on mortgage-backed securities.

CNN and Daily Finance, however, seem to be disagreeing with each other as to how much value may still be lost in some homes. CNN seems certain homes will not lose more than another five percent in value, basing their insight on what renters are paying. Daily Finance claims as much as forty percent, based on average income.