(1) All rates shall be made in accordance with this section and all of the following:

  (a) Due consideration shall be given to past and prospective loss experience within and outside this state; to catastrophe hazards; to a reasonable margin for underwriting profit and contingencies; to dividends, savings, or unabsorbed premium deposits allowed or returned by insurers to their policyholders, members, or subscribers; to past and prospective expenses, both countrywide and those specially applicable to this state; to underwriting practice, judgment, and to all other relevant factors within and outside this state. Experience rating is permitted for groups.

  (b) The systems of expense provisions included in the rates for use by any insurer or group of insurers may differ from those of other insurers or groups of insurers to reflect the requirements of the operating methods of the insurer or group with respect to any kind of insurance, or with respect to any subdivision or combination thereof for which subdivision or combination separate expense provisions are applicable.

  (c) 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 which measure variations in hazards, expense provisions, or both. The rating plans may measure any differences among risks that may have a probable effect upon losses or expenses as provided for in subdivision (a).

  (d) Rates shall not be excessive, inadequate, or unfairly discriminatory. A rate shall not be held to be excessive unless the rate is unreasonably high for the insurance coverage provided and a reasonable degree of competition does not exist with respect to the classification, kind, or type of risks to which the rate is applicable. A rate shall not be held to be inadequate unless the rate is unreasonably low for the insurance coverage provided and the continued use of the rate endangers the solvency of the insurer; or unless the rate is unreasonably low for the insurance provided and the use of the rate has or will have the effect of destroying competition among insurers, creating a monopoly, or causing a kind of insurance to be unavailable to a significant number of applicants who are in good faith entitled to procure the insurance through ordinary methods. A rate for a coverage is unfairly discriminatory in relation to another rate for the same coverage, if the differential between the rates is not reasonably justified by differences in losses, expenses, or both, or by differences in the uncertainty of loss for the individuals or risks to which the rates apply. A reasonable justification shall be supported by a reasonable classification system; by sound actuarial principles when applicable; and by actual and credible loss and expense statistics or, in the case of new coverages and classifications, by reasonably anticipated loss and expense experience. A rate is not unfairly discriminatory because the rate reflects differences in expenses for individuals or risks with similar anticipated losses, or because the rate reflects differences in losses for individuals or risks with similar expenses. Rates are not unfairly discriminatory if they are averaged broadly among persons insured on a group, franchise, blanket policy, or similar basis.

  (2) Except to the extent necessary to meet the provisions of subsection (1)(d), uniformity among insurers in any matters within the scope of this section is neither required nor prohibited.

  (3) Rates shall be considered excessive if the insurer fails to annually file an actuarial certification that the legal expense policies are expected to return to policyholders in the form of aggregate benefits under the policy, as estimated for the entire period for which rates are computed to provide coverage, on the basis of incurred claims experience and earned premiums for that period, and in accordance with accepted actuarial principles and practices, the following:

  (a) In the case of group policies other than group employee benefit policies, at least 75% of the aggregate amount of premiums collected.

  (b) In the case of individual policies, at least 65% of the aggregate amount of premiums collected.