"Statewide average weekly wage" means the amount computed by the department as of July first of each year that is the aggregate amount of wages, irrespective of the limitation on the amount of wages subject to contributions by reason of § 41-27-380(2), reported by employers as paid during the first four of the last six completed calendar quarters before this date, divided by a figure representing fifty-two times the twelve-month average of the number of employees in the pay period containing the twelfth day of each month during the same four calendar quarters as reported by those employers.