Requirement to keep records and to report. Subject to the provisions of this law, every employer shall keep an accurate record of the number and job classification of his employees and the wages paid, and upon demand of the commission shall furnish the commission a sworn statement of the same. Such records shall not be open to inspection except on request of the commission. The commission shall have the right, at any time and as often as it requires, to verify the number of employees and the amount of the payroll, and to inspect or cause to be inspected such records.