Mortgage rates in the U.S. once again dipped to a record low.

The average for a 30-year, fixed loan dropped to 2.8%, down from 2.81% last week and the lowest in almost 50 years of data-keeping, Freddie Mac said in a statement Thursday. It was the 11th record low this year. The previous one held for a week.

The plunge in borrowing costs began in March as the coronavirus roiled financial markets. The lower rates have fueled a housing rally that has boosted the pandemic-battered U.S. economy.

Home sales have surged as Americans look for more space in the suburbs. But the lower mortgage rates have combined with scarce inventory to drive up prices, possibly pushing homeownership out of reach for many.