287.950.  Competitive market, rates not to be excessive, inadequate, unfairly discriminatory. — 1.  Rates in a competitive market shall not be excessive, inadequate or unfairly discriminatory.  Rates are excessive if it is likely to produce a long-run profit that is unreasonably high for the insurance provided or if expenses are unreasonably high in relation to services rendered.  Rates are not inadequate unless clearly insufficient to sustain projected losses and expenses and the use of such rates, if continued, will tend to create a monopoly in the market.  A rate is inadequate if funds equal to the full ultimate cost of anticipated losses and loss adjustment expenses are not produced when the prospective loss costs are applied to anticipated payrolls.

  2.  Unfair discrimination exists if, after allowing for practical limitations, price differentials fail to reflect equitably the differences in expected losses and expenses.  A rate is not unfairly discriminatory because different premiums result for policyholders with like loss exposures but different expenses, or like expenses but different loss exposures, so long as the rate reflects the differences with reasonable accuracy.