Freddie Mac has released the results of its Primary Mortgage Market Survey (PMMS), showing fixed mortgage rates mixed following data reports on inflation and the housing construction market, as the 30-year fixed-rate mortgage (FRM) averaged 3.37 percent with an average 0.7 point for the week ending Dec. 20, 2012, up from last week when it averaged 3.32 percent. Last year at this time, the 30-year FRM averaged 3.91 percent. Also last week, the 15-year FRM averaged 2.65 percent with an average 0.7 point, down from last week when it averaged 2.66 percent. A year ago at this time, the 15-year FRM averaged 3.21 percent. "Mortgage rates were mixed this week following data reports on stable inflation and a thriving home construction market," said Frank Nothaft, vice president and chief economist for Freddie Mac. "The 12-month growth in the core consumer price index has remained between 1.9 and 2.1 percent for the past five consecutive months ending in November. Meanwhile, housing starts averaged the strongest three months in November since September 2008, and homebuilder confidence rose in December to its highest reading since April 2008." The five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 2.71 percent this week with an average 0.7 point, up from last week when it averaged 2.70 percent. A year ago, the five-year ARM averaged 2.85 percent. The one-year Treasury-indexed ARM averaged 2.52 percent this week with an average 0.4 point, down from last week when it averaged 2.53. At this time last year, the one-year ARM averaged 2.77 percent.