-If the three interest rate fields on the Main tab (Incremental borrowing rate, Interest rate, and Implied rate) all contain values, the Implied rate is used.
-If the Implied rate is 0, then the Incremental borrowing rate is used, even if the Interest rate field has a value.
-If the Interest rate field is the only one with a value, that rate is used.
-If all three of these rate fields are empty, this rate is not updated.