The board of supervisors shall determine the bona fide yearly subscribers of a newspaper within the county, as follows:
 1. Those subscribers listed by the publisher whose papers are delivered, by or for the publisher, by mail or otherwise, upon an order or subscription for same by the subscriber, and in accordance with the postal laws and regulations, and who have been subscribers at least six consecutive months prior to date of application.
 2. Those subscribers who have been subscribers at least six consecutive months before the date of application, whose papers are regularly delivered by carrier upon an order or subscription, or whose papers are purchased from the publisher for resale and delivery by independent carriers who have filed with the publisher a list of their subscribers.