According to the  article, "Freddie Mac said Thursday the rate on the 30-year loan dropped from 4.10 percent last week. Four weeks ago, it dropped to 3.94 percent — the lowest rate ever, according to the National Bureau of Economic Research. 
The average rate on the 15-year fixed mortgage fell to 3.31 percent from 3.38 percent. Four weeks ago, it too hit a record low of 3.26 percent."

(Source: Monterey