WASHINGTON (AP) — Interest rates on short-term U.S. Treasury bills were mixed in Monday’s auction.

The Treasury Department auctioned $51 billion in three-month bills at a discount rate of 1.97 percent, down from 1.98 percent last week. Another $45 billion in six-month bills was auctioned at a discount rate of 2.14 percent, unchanged from last week.

The rates on both bills remain near their highest levels since the 2008-2009 recession.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,950.20 while a six-month bill sold for $9,891.81. That would equal an annualized rate of 2.007 percent for the three-month bills and 2.193 percent for the six-month bills.

Separately, the Federal Reserve said Monday that the average yield for one-year Treasury bills, a popular index for making changes in adjustable-rate mortgages, stood at 2.41 percent Friday, up from 2.39 percent at the beginning of last week, July 16.