In this section, “percentage preference” means the percent of the lowest responsive bid submitted by a responsible bidder who is not a small business by which a responsive bid by a small business may: exceed the lowest bid; and be awarded a procurement contract under this subtitle. Subject to the approval of the Board, each unit: shall establish a percentage preference, not to exceed 8%, for each industry as follows: a base percentage preference not to exceed 5% for all small businesses; and two additional preferences to the percentage preference set forth in item (i) of this paragraph as follows: 2% for veteran–owned small businesses; and 3% for disabled veteran–owned small businesses; and may vary the percentage preference determined in item (1)(i) of this subsection among industries to account for their particular characteristics.