NEW YORK, June 18 (Reuters) – U.S. mortgage rates dropped in the latest week, retreating sharply from a seven-month high as fears over inflation abated and Treasury yields dropped.

Interest rates on U.S. 30-year fixed-rate mortgages plunged to 5.38 percent for the week ending June 18, according to a survey released on Thursday by home funding company Freddie Mac.

A year ago, 30-year mortgage rates averaged 6.42 percent, 15-year mortgages were at 6.02 percent and the one-year ARM was at 5.19 percent. A year ago, the 5/1 ARM averaged 5.89 percent.

Rates on conforming mortgages fell again this week, with the 30-year fixed-rate mortgage hitting a record low of 4.78% for the week ending April 2, according to Freddie Mac’s weekly survey results released Thursday.

30-year fixed-rate, 15-year fixed-rate and 5-year ARM hit record lows

The 30-year fixed-rate mortgage averaged 4.85% last week, and 5.88% a year ago. This week, it’s at its lowest level since the survey began in 1971.

Rates on 15-year fixed-rate mortgages also hit a record low, averaging 4.52% this week. The mortgage averaged 4.58% last week and 5.42% a year ago. It hasn’t been lower since Freddie Mac began tracking the mortgage in 1991.

Five-year Treasury-indexed hybrid adjustable-rate mortgages averaged 4.92%, another record low; Freddie Mac has tracked this mortgage since 2005. The ARM averaged 4.96% last week and 5.59% a year ago.