The 15-year fixed-rate mortgage reached a new all-time low this week, while the 30-year mortgage edged nearer to matching its record low, Freddie Mac reports in its weekly mortgage market survey.

The low mortgage rates are helping to push housing affordability to record highs. The National Association of REALTORS® reported this week that the average family has more than double the income needed to purchase a median-priced home.

Here’s a closer look at rates for the week ending March 8:

• 30-year fixed-rate mortgages: averaged 3.88 percent — only 0.01 percentage points above its previous all-time low. A year ago, 30-year rates averaged 4.88 percent.
• 15-year fixed-rate mortgages: averaged a new record low of 3.13 percent, with an average 0.8 point, dropping from last week’s 3.17 percent average. The previous record low for the 15-year mortgage was set in February when it reached 3.14 percent. Last year at this time, 15-year rates, a popular choice among refinancers, averaged 4.15 percent.
• 5-year adjustable-rate mortgages: averaged 2.81 percent, with an average 0.7 point, falling from last week’s 2.83 percent average. Last year at this time, 5-year ARMs averaged 3.73 percent.
• 1-year ARMs: averaged 2.73 percent this week, with an average 0.6 point, rising slightly from last week’s 2.72 percent average. A year ago at this time, 1-year ARMs averaged 3.21 percent.