Mortgage rates dropped this week for both long- and short-term rates, according to Freddie Mac. A 30-year, fixed-rate mortgage averaged 4.77% with an average 0.8 point for the week ending Jan. 6, down from 4.86% a week ago. Last year at this time, the 30-year rate averaged 5.09%. A 15-year, fixed-rate loan averaged 4.13% with an average 0.8 point, down from 4.2% a week ago. A year ago, the 15-year FRM averaged 4.5%. Freddie said the five-year Treasury-indexed hybrid adjustable-rate mortgage averaged 3.75%, with an average 0.7 point, down from 3.77% last week and 4.44% a year ago. A one-year Treasury-indexed ARM averaged 3.24% with an average 0.6 point, down from 3.26% last week and 4.31% in the year-ago period. Frank Nothaft, vice president and chief economist at Freddie Mac, said the low rates “remained below those at the start of 2010, which should help aid the recovery in the housing market.” Housing affordability in November was the highest since records began in 1971, according to the National Association of Realtors. NAR said that pending existing home sales rose for the second consecutive month in November to the strongest pace since April when the homebuyer tax credit expired. Mortgage applications for home purchases at the end of 2010 were roughly running at the same rate as the beginning of the year, according to the Mortgage Bankers Association. Write to Kerry Curry.