1. The state auditor may audit each district not more than once every three years. The actual costs of this audit shall be paid by the district except that the costs of the audit to the district shall not exceed three percent of the gross revenues received by the district. Any audit costs in excess of three percent of the gross revenue received by the district shall be absorbed by the state auditor’s office.

2. For petition audits performed on a district by the state auditor, all expenses incurred in performing the audit including salaries of auditors, examiners, clerks, and other employees of the state auditor shall be paid by the district, and the moneys shall be deposited in the petition audit revolving trust fund under section 29.230. The actual costs of this audit shall be paid by the district except that the costs of the audit to the district shall not exceed three percent of the gross revenues received by the district. Any audit costs in excess of three percent of the gross revenue received by the district shall be absorbed by the state auditor’s office.