As used in this act:
(a) "Kansas export transaction" means a transaction for the export of products substantially manufactured or processed within Kansas or services which result in additional employment within Kansas from Kansas to a destination outside the 50 states of the United States of America;
(b) "preexport" means the period of time between the formation of a Kansas export transaction and the actual shipment of the products or performance of the services; and
(c) "postexport" means the period of time between a shipment of products or performance of services for a Kansas export transaction and the receipt of final payment therefor.