Each employer shall keep a record of the names and addresses of all student learners and employees, the hours of employment and wages of each, and such other records pertaining to ability as the department requires, except that an employer is not required to keep a record of the hours of employment of an employee who is exempt under rules promulgated by the department from the requirement under s. 103.02 that an employee be paid overtime compensation, as defined in s. 103.025 (1) (c), and who is not compensated on an hourly rate basis.