Discount Rules for Multiples of X Units

Ability to have automated discount rules for B2B customers ordering in multiples of X units to suit full-box quantities. 

E.g., Customer orders a product in multiples of 12 (a full box) and receives 10% off. If they order 18, they will only receive 10% off on the 12. If they order 24, they will receive 10% off 2x 12 units.