The rates and premiums paid by employers insured in the fund must not be excessive, inadequate, or unfairly discriminatory. Employers may be grouped by classifications for the establishment of rates and minimum premiums, and classification rates may be modified to produce rates for individual employers in accordance with rating laws which establish standards for measuring any variations in hazards or expense provisions, or both, that can be demonstrated to have a probable effect upon losses or expenses. All premiums collected by the fund must be deposited by it in the State Treasurer to the credit of the State Accident Fund.