(a) The Commission may upon direction of the Board from time to time assess each of the private self-insurers a pro rata share of the funding reasonably necessary to carry out its activities under Sections 4a-1 through 4a-9. The prorations shall be made on the basis of each self-insured’s most recent payment into the rate adjustment fund under Section 7(f) of this Act. In no event shall a private self-insurer be assessed at one time in excess of .6% of the compensation paid by that private self-insurer during the previous calendar year for claims incurred as a self-insurer. Total assessments against it in any calendar year shall not exceed 1.2% of the compensation it has paid during the previous calendar year as a self-insurer for claims incurred. Funds obtained by such assessments shall be used only for the purposes set forth in Sections 4a-1 through 4a-9, and shall be deposited upon receipt by the Commission into the Self-Insurers Security Fund. If payment of any assessment made under this subsection is not made within 30 days of the sending of the notice to the private self-insurer, the Commission at the direction of the Board shall proceed in circuit court for judgment against that private self-insurer which judgment shall include the amount of the assessment, the costs of suit, interest and reasonable attorneys’ fees.
     (b) A private self-insurer which ceases to be a self-insurer shall be liable for any and all assessments made pursuant to this Section during the period following the date its certificate of authority to self-insure is withdrawn, revoked or surrendered until such time as it has discharged all obligations to pay compensation which arose during the period of time said former self-insurer was self-insured. Assessments of such a former private self-insurer shall be based on the compensation paid by the former private self-insurer during the preceding calendar year on claims that arose during the period of time said former private self-insurer was self-insured.
     (c) The Board on behalf of the Commission shall annually contract for an independent certified audit of the financial activities of the Fund, and an annual report as of June 30 shall be submitted promptly by the Board to the Chairman of the Illinois Workers’ Compensation Commission and to each Trustee. Written reports of all activities shall be submitted to the Commission by the Board on a monthly basis.
     (d) If there are monies remaining in the Fund after all outstanding obligations of all insolvent self-insurers have been satisfied and the costs of administration and defense have been paid, such amounts shall be returned by the Commission from the Fund as directed by the Board to the then private self-insurers in that proportion which each said private self-insurer has contributed to the Fund one year thereafter, provided no outstanding liabilities remain against the Fund.
     (e) Each private self-insurer shall be subject to the direction of the Commission as provided in Sections 4a-1 through 4a-9 as a condition of obtaining and maintaining its certificate of authority to self-insure.