The director shall apply the following standards in making rates:

(1)  Rates shall not be excessive, inadequate, or unfairly discriminatory.

(2)  Due consideration shall be given to: (i) past and prospective loss experience within and outside the state; (ii) a reasonable margin for profits and contingencies; (iii) dividends, savings, or unabsorbed premium deposits allowed or returned by insurers to their policyholders, members, or subscribers; (iv) past and prospective expenses both countrywide and those specifically applicable to this state; (v) provisions for special assessments; and (vi) all other relevant factors within and outside this state. In determining the reasonableness of the profit, consideration shall be given to investment income.

(3)  Risks may be grouped by classifications for the establishment of rates and minimum premiums. Classification rates may be modified to produce rates for individual risks in accordance with rating plans that establish standards for measuring variations in hazards or expense provisions, or both. These standards may measure any differences among risks that can be demonstrated to have a probable effect upon losses or expenses.