Rating methods.

In determining whether rates comply with the rate standards, the following criteria shall be applied: A. due consideration shall be given to past and prospective loss and expense experience within and without this state, to catastrophic hazards and contingencies, to trends within and without this state, to loadings for leveling premium rates over time or for dividends or savings to be allowed or returned by insurers to their policyholders, members or subscribers and to all other relevant factors, including the judgment of technical personnel; B. risks may be classified in any reasonable way for the establishment of rates and minimum premiums, except that classifications may not be based on race, color, creed or national origin; C. the expense provisions included in the rates to be used by an insurer may reflect the operating methods of the insurer and, so far as it is credible, its own expense experience; and D. the rates may contain an allowance permitting a profit that is not unreasonable in relation to the riskiness of the line, kind or class of business. Profit shall include investment income attributable to such rates.