The annual salary of each commissioner shall be fifty-five hundred dollars plus any salary adjustment provided pursuant to section 105.055. The salary of the secretary to the commission and the salaries of all other commission employees shall be such as may from time to time be fixed by the commission. The commissioners and all employees of the commission shall have reimbursed to them all actual and necessary traveling and other expenses and disbursements incurred or made by them in the discharge of their official duties while away from their regular offices in the performance of such duties.