6. The number of electoral divisions shall vary from 9 to 27 according to the number of electors of the school board established in the document referred to in section 7.4. There shall be(1) 9 divisions if there are fewer than 5,000 electors;
(2) 11 divisions if there are 5,000 electors or more but fewer than 10,000;
(3) 13 divisions if there are 10,000 electors or more but fewer than 20,000;
(4) 15 divisions if there are 20,000 electors or more but fewer than 30,000;
(5) 17 divisions if there are 30,000 electors or more but fewer than 40,000 ;
(6) 19 divisions if there are 40,000 electors or more but fewer than 70,000;
(7) 21 divisions if there are 70,000 electors or more but fewer than 100,000;
(8) 23 divisions if there are 100,000 electors or more but fewer than 150,000;
(9) 25 divisions if there are 150,000 electors or more but fewer than 250,000;
(10) 27 divisions if there are 250,000 electors or more.