b) Supporting documentation shall include, at a minimum:

1. 1) Copies of all cancelled checks. If cancelled checks are not available, an affidavit from the recipient that payment was made;
2. 2) An itemization of all direct costs and unit rates for each direct cost item;
3. 3) A list of employees by classification, time spent by each employee on the project for the invoice service period, and the hourly rate of each employee; and
4. 4) The low bid amount and award date, if applicable.