(a) Each applicant for a permit or the renewal of a permit under this part shall pay an annual fee established by the Administration, based as to each outdoor sign on the area of its advertising surface.
(b) If a permit is issued in any month after May, the fee for that permit shall be prorated according to the number of months, including the month of its issuance, that remain in the license year, but the fee may not be less than $1.