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 at least eight but not more than nine grower members, and any such change shall be based, so far as practicable, upon the respective averages for the immediately preceding five fiscal periods of (1) the volume of fruit shipped from each district; (2) the volume of fruit produced in each district; and (3) the total number of acres of citrus in each district. The committee shall consider such redistricting and reapportionment during the 1980-81 fiscal period, and only in each fifth fiscal period thereafter, and each such redistricting or reapportionment shall be announced on or before March 1 of the then current fiscal period. [42 FR 59368, Nov. 17, 1977]