The rates made by each insurer or rating organization shall be subject to the following provisions:

(1) Rates shall not be excessive or inadequate, as herein defined, nor shall they be unfairly discriminatory;

(2) No rate shall be held to be excessive unless such rate is unreasonably high for the insurance provided and a reasonable degree of competition does not exist in the area with respect to the classification to which such rate is applicable;

(3) No rate shall be held to be inadequate unless such rate is unreasonably low for the insurance provided and the continued use of such rate endangers the solvency of the insurer using the same, or unless such rate is unreasonably low for the insurance provided and the use of such rate by the insurer using same has, or if continued will have, the effect of destroying competition or creating a monopoly;

(4) Due consideration shall be given to past and prospective loss experience within this state and consideration may also be given to past and prospective loss experience outside this state to the extent appropriate. Each insurer and rating organization may also give consideration to physical hazards, to catastrophe hazards, if any, 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 especially applicable to this state, and to any other factors within or outside this state which the insurer or rating organization deems relevant to the making of rates;

(5) 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 any such 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;

(6) 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 standards for measuring variations in hazards or expense provisions, or both. Such standards may measure any differences among risks that can be demonstrated to have a probable effect upon losses or expenses. Classifications or modifications of classification or any portion or any division thereof, of risks may be predicated upon size, expense, management, individual experience, purpose of insurance, location or dispersion of hazard, or any other reasonable considerations, provided such classifications and modifications shall be applicable to the fullest practicable extent to all risks under the same or substantially the same circumstances or conditions. Classification rates may also be modified to produce rates for individual or special risks which are not susceptible to measurement by any established standards;

(7) Except to the extent necessary to meet the provisions of subdivision (1) of this section, uniformity among insurers in any matters within the scope of this section is not required;

(8) Any rate, rating schedule, rating system, or rating plan may return or refund a portion of its expense savings to the insured if the insured makes no reportable claim under specified coverages within a prescribed period of time established by the insurer, regardless of whether such claim is due to the fault of the insured. Such return of savings may be represented as a predetermined portion of the premium, and shall not constitute a rebate or an unfair trade practice under sections 375.930 to 375.948.