If death results from the personal injury of an employee, the employer shall pay, or cause to be paid, subject to section 375, in 1 of the methods provided in this section, to the dependents of the employee who were wholly dependent upon the employee’s earnings for support at the time of the injury, a weekly payment equal to 80% of the employee’s after-tax average weekly wage, subject to the maximum and minimum rates of compensation under this act, for a period of 500 weeks from the date of death. If at the expiration of the 500-week period any such wholly or partially dependent person is less than 21 years of age, a worker’s compensation magistrate may order the employer to continue to pay the weekly compensation or some portion thereof until the wholly or partially dependent person reaches the age of 21. If the employee leaves dependents only partially dependent upon his or her earnings for support at the time of injury, the weekly compensation to be paid shall be equal to the same proportion of the weekly payments for the benefit of persons wholly dependent as 80% of the amount contributed by the employee to the partial dependents bears to the annual earnings of the deceased at the time of injury.