MCLEAN, Va. -- For the week ending Oct. 16, 30-year fixed-rate mortgages averaged 6.46% with an average 0.6 point, up from last week when it averaged 5.94%. This week's 52 basis points increase is the largest weekly increase in 20 years, according to Freddie Mac's Primary Mortgage Market Survey.

Last year at this time, the 30-year fixed-rate mortgage interest rate averaged 6.40%.

The 15-year fixed-rate mortgage this week averaged 6.14% with an average 0.6 point, up from last week when it averaged 5.63%. A year ago at this time, the 15-year fixed-rate mortgage averaged 6.08%.

Five-year Treasury-indexed hybrid adjustable-rate mortgages averaged 6.14% this week, with an average 0.6 point, up from last week when it averaged 5.90%. A year ago, the 5-year ARM averaged 6.11%.

One-year Treasury-indexed ARMs averaged 5.16% this week with an average 0.6 point, up from last week when it averaged 5.15%. At this time last year, the 1-year ARM averaged 5.76%.

More than half of the panelists surveyed by Bankrate.com for the week of Oct. 16 to Oct. 22 expect rates to decline over the next 35 to 45 days.