Mortgage rates were back to hitting record lows again, pushing housing affordability even higher to home buyers, Freddie Mac reports in its weekly mortgage market survey. For the sixth consecutive week, the 30-year fixed-rate mortgage, the most popular choice among buyers, has averaged below 4 percent — unheard of until a few weeks ago.

"Mortgage rates eased slightly this week to all-time record lows following mixed indicators in the labor market,” Frank Nothaft, chief economist at Freddie Mac, said in a statement. The economy added 1.6 million jobs in 2011 — the highest number since 2006 — but overall unemployment still remains high, Nothaft noted.

Here’s a closer look at rates and the new record lows they posted for the week ending Jan. 12:

• 30-year fixed-rate mortgages: averaged 3.89 percent, with an average 0.7 point, reaching a new all-time low. Previously, 30-year mortgages’ record low was last week’s 3.91 percent average. A year ago at this time, 30-year rates averaged 4.71 percent.
• 15-year fixed-rate mortgages: averaged 3.16 percent, with an average 0.8 point, dropping from last week’s 3.23 percent average. Last year at this time, 15-year rates averaged 4.08 percent.
• 5-year adjustable-rate mortgages: averaged 2.82 percent, with an average 0.7 point, dropping from last week’s 2.86 percent average. Last year at this time, 5-year ARMs averaged 3.72 percent.
• 1-year ARMs: averaged 2.76 percent, with an average 0.6 point, this week, falling from last week’s 2.80 percent average. A year ago, 1-year ARMs averaged 3.23 percent.

Source: Freddie Mac