Ecology shall divide allowances that are to be auctioned into lots in accordance with the following rules:

(1) Each lot, other than the final lot for each vintage, shall consist of 1,000 allowances.

(2) The final lot may consist of fewer than 1,000 allowances if fewer than 1,000 allowances remain once all other allowances have been divided into lots of 1,000.

(3) Each lot of future vintage allowances must consist of only one vintage of allowances.

(4) Each lot other than lots of future vintage allowances may include both current and past vintage allowances.