Although the Treasury yield has increased 12 basis points over the last week, the mortgage rates have been slow to adjust. They remain at a 3 year low, but continue to inch upwards on weekly basis, according Mortgage Giant, Freddie Macs' Prime Mortgage Market Survey (PMMS).

The survey reveals the following:

30-year fixed-rate mortgage (FRM) averaged 3.56 percent with an average 0.6 point for the week ending June 23, 2016, showing a slight rise from last week when it averaged 3.54 percent.

15-year FRM this week averaged 2.83 percent with an average 0.5 point, showing a rise from last week when it averaged 2.81 percent.

5/1-year ARM averaged 2.74 percent this week with an average 0.5 point and a 2.74 margin, remaining unchanged from the week before.

Due to the low rates, the existing home sales continue to rise 1.8 percent to a 5.53 million seasonally adjusted rate in May of this year, this marks the highest level since February of 2007.If you are in the market to buy a new home or to refinance the one you own, now is a great time to lock in a rate.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country at the beginning of each week. The average doesn't include extra fees, known as points, which most borrowers must pay to get the lowest rates. One point equals 1 percent of the loan amount.