No permit will be issued unless the applicant shall place on file with the Clerk-Treasurer a policy of insurance in full force and effect, issued by a responsible and reputable company authorized to do business in the State of Indiana, insuring the owner of the sign against personal liability to the extent of $50,000 for injury and death to any one person and $130,000 for injury and death to two or more persons. The policy of insurance must remain in full force and effect at all times.
(`77 Code, § 23.12)