141.991.  Annual audit — performance audits, when. — There shall be an annual audit of the affairs, accounts, expenses, and financial transactions of a land bank agency by certified public accountants as of April thirtieth of each year, which accountants shall be employed by the commissioners on or before March first of each year, and certified copies thereof shall be furnished to the appointing authorities described in section 141.981, and shall be available for public inspection at the office of the land bank agency.  In addition to the annual audit provided for in this subdivision, the land bank agency may be performance audited at any time by the state auditor or by the auditor of the municipality that established the land bank agency.  The cost of such audit shall be paid by the land bank agency and copies shall be made available to the public within thirty days of the completion of the audit.