The committee may recommend, and pursuant thereto the Secretary may approve, the reapportionment of members among districts, the reapportionment of members between grower and handler members representing cooperative marketing organizations and independent grower and independent handler members, and the re-establishment of districts within the production area. In recommending such changes, the committee shall give consideration to: (a) Shifts in production; (b) the importance of new production in its relation to existing districts; (c) the equitable relationship of committee membership and districts; (d) changes in amount of fruit handled by cooperative marketing organizations in relation to fruit handled by independent handlers; and (e) other relevant factors. No changes in districting or in apportionment of members may become effective in less than 30 days prior to the date on which terms of office begin each year and no recommendations for such redistricting or reapportionment may be made less than six months prior to such date.