(a) The Committee may, with the approval of the Secretary, redefine the districts into which the production area is divided or reapportion or otherwise change the grower membership of districts, or both: Provided, That the membership shall consist of 10 grower members, and any such change shall be based, insofar as practicable, upon the respective averages for the immediately preceding three fiscal periods of:

(1) The number of bearing trees in each district;

(2) The volume of fresh fruit produced in each district;

(3) The total number of acres of citrus in each district; and

(4) Other relevant factors.

(b) Each redistricting or reapportionment shall be announced on or prior to March 1 preceding the effective fiscal period.