A supplemental nursing services agency must not bill or receive payments from a nursing home licensed under this chapter at a rate higher than 150 percent of the sum of the weighted average wage rate, plus a factor determined by the commissioner to incorporate payroll taxes as defined in Minnesota Rules, part 9549.0020, subpart 33, for the applicable employee classification for the geographic group to which the nursing home is assigned under Minnesota Rules, part 9549.0052. The weighted average wage rates must be determined by the commissioner of human services and reported to the commissioner of health on an annual basis. Wages are defined as hourly rate of pay and shift differential, including weekend shift differential and overtime. Facilities shall provide information necessary to determine weighted average wage rates to the commissioner of human services in a format requested by the commissioner. The maximum rate must include all charges for administrative fees, contract fees, or other special charges in addition to the hourly rates for the temporary nursing pool personnel supplied to a nursing home.