HOUSTON (Houston Business Journal) – Thirty-year mortgage rates fell to 4.78 percent Friday, hitting their lowest level since Freddie Mac started tracking rates in 1970.

Adjustable-rate mortgages also eased, but one-year, adjustable-rate mortgages are averaging rates nearly the same as 30-year fixed rates, at 4.77 percent.

Freddie Mac officials reported borrowers who refinanced their mortgages in the first quarter reduced their combined mortgage payments by about by about $2.5 billion over the coming year.