Mortgage rates rose for the third consecutive week, causing demand from both current homeowners and potential homebuyers to drop. Total mortgage application volume fell 5.2% last week compared with the previous week, according to the Mortgage Bankers Association's seasonally adjusted index. The average contract interest rate for 30-year fixed-rate mortgages with conforming loan balances, $806,500 or less, increased last week to 6.37% from 6.34%, with points remaining unchanged at 0.62,