If after lay-offs have occurred, and for a period of one calendar year after the 30th day of September following the date of lay-off, teachers who have been laid off and have given notice by registered mail under Article 16.05 above shall be offered the position first as it becomes available when positions become vacant provided such teachers have the necessary training, academic qualifications and experience for the positions available. Length of teaching service with the Board will be used to determine the order in which the laid-off teachers are offered the available positions provided that said teachers have the necessary training, academic qualifications and experience.