By now, you would think just about everyone had refinanced their mortgage to today’s historically low-interest rates, but apparently not.

Refinance volume drove total mortgage application activity 3.8% higher last week compared with the previous week, according to the Mortgage Bankers Association’s seasonally adjusted index. Volume was 63% higher than the same week one year ago.

Applications to refinance a home loan jumped 9% for the week and were 146% higher than the same week one year ago. The average rate on the 30-year fixed was 98 basis points higher a year ago. The refinance share of mortgage activity increased to 62.4 percent of total applications from 59.0 percent the previous week.

Refinance volume has been incredibly strong all year — 17% of the total active mortgage market, according to real estate analytics company Black Knight. A growing number of borrowers is now doing cash-out refinances, something that was unpopular over the last decade of the housing recovery.

Mortgage rates were essentially flat last week from the previous week, with the average contract interest rate for 30-year fixed-rate mortgages with conforming loan balances ($484,350 or less) increasing to 3.98% from 3.97%, with points increasing to 0.33 from 0.32 (including the origination fee) for loans with a 20% down payment.

“The 30-year fixed mortgage rate remained under 4% for the fourth straight week, and rates for FHA loans declined close to their lowest level of the year,” said Joel Kan, MBA’s associate vice president of economic and industry forecasting. “The decrease in FHA rates led to a 27% jump in refinance applications for those loans, and their share of refinance activity — at 14%— was the highest since 2016.”

Mortgage applications to purchase a home fell 0.4% for the week but were 5% higher than a year ago.

“The November jobs data showed increased payroll gains and low unemployment, which means conditions remain favorable for steady purchase growth in the coming months,” added Kan.

While economic conditions may be favorable, the current for-sale market is not. The housing shortage is getting worse, as fewer homes than normal came on the fall market. Supply is leanest at the lower end of the market, where demand is strongest.

Mortgage rates have been moving in a narrow range lately, and Wednesday afternoon’s announcement on interest rates by the Federal Reserve is not expected to change that. Rates are going to be much more responsive to the Dec. 15 deadline for additional U.S. tariffs on Chinese goods.

“In general, a delay or cancellation would be bad for rates, but markets are already expecting a delay to some extent,” wrote Matthew Graham, chief operating officer at Mortgage News Daily. “The bigger deal would be waking up Monday morning of next week to find the tariff hike had been implemented. In that case, rates would likely benefit (i.e. move lower!).”