The Council may recommend, subject to approval of the Secretary, reestablishment of regions, reapportionment of members among regions, and may revise the groups eligible for representation on the Council. In recommending any such changes, the following shall be considered:

(a) Shifts in acreage within regions and within the production area during recent years;

(b) The importance of new production in its relation to existing regions;

(c) The equitable relationship between Council apportionment and regions;

(d) Changes in industry structure and/or the percentage of crop represented by various industry entities; and

(e) Other relevant factors.