The interest rate for a 30-year, fixed-rate mortgage remained at a 16-month low last week, continuing a trend of sub-4% interest rates, according to a new report from Zillow (Z). 

Current rate borrowers were quoted an average interest rate of 3.81% on Zillow’s Mortgage Marketplace in the week that ended Tuesday, which equaled the previous week’s figure of 3.81%.

 The previous week’s total was down from 3.96%, leaving interest rates at below 4% for three weeks running.

According to Zillow’s report, the 30-year fixed mortgage rate hovered around 3.85% for most of the week, dropping to 3.7% last Wednesday and then rising back up the current rate.

“Last week mortgage rates experienced dramatic inter-day volatility, falling Wednesday to their lowest level since May 2013 fueled by global economic concerns and the potential threat of an Ebola epidemic,” said Erin Lantz, vice president of mortgages at Zillow. “With little mortgage market-moving data scheduled to be released next week, we expect rates to remain stable.”

Zillow also reported that the 15-year fixed mortgage rate continued below 3% last week, sitting at 2.97% as of Tuesday morning. The rate for 5/1 adjustable rate mortgages was 2.8%, up slightly from last week’s figure of 2.7%.