A supplier will give Shark Unibase Company a discount of 2% if an invoice is paid 60 days before its due date. Suppose Shark wants to take advantage of this discount but needs to borrow the money. It plans to pay back the loan in 60 days. What is the highest annual simple interest rate at which Shark Unibase can borrow the money and still save by paying the invoice 60 days before its due date? 9