– A renewal period within the meaning of this act is considered as being a period of two years from the date of expiration of a previously issued license. The department shall require any applicant, who does not apply for renewal of license within such period, to qualify by passing the written examination as provided herein, and may require any licensee who has not yet passed the written examination, and who cannot reasonably prove to the satisfaction of the department, that he can meet the competency requirements, to pass the written examination before a renewal of license shall be granted;