(1) An insurer may file with the commissioner a rate filing that provides for a program with more than one rate level in the same company or group of companies if:
(a) the program is based, to the extent feasible, upon mutually exclusive underwriting rules per tier;
(b) the underwriting rules are based on clear, objective criteria that would lead to a logical distinguishing of potential risk; and
(c) in filing to establish tiers, the insurer provides supporting information that evidences a clear distinction between the expected losses and expenses for each tier.
(2) A rating tier may not be continued if premium, loss, and expense data fail to show a continued clear distinction between the tiers.