(1) The weekly loss in wages referred to in this act shall consist of the percentage of the average weekly earnings of the injured employee computed according to this section as fairly represents the proportionate extent of the impairment of the employee’s earning capacity in the employments covered by this act in which the employee was working at the time of the personal injury. The weekly loss in wages shall be fixed as of the time of the personal injury, and determined considering the nature and extent of the personal injury. The compensation payable, when added to the employee’s wage earning capacity after the personal injury in the same or other employments, shall not exceed the employee’s average weekly earnings at the time of the injury.

  (2) As used in this act, “average weekly wage” means the weekly wage earned by the employee at the time of the employee’s injury in all employment, inclusive of overtime, premium pay, and cost of living adjustment, and exclusive of any fringe or other benefits which continue during the disability. Any fringe or other benefit which does not continue during the disability shall be included for purposes of determining an employee’s average weekly wage to the extent that the inclusion of the fringe or other benefit will not result in a weekly benefit amount which is greater than 2/3 of the state average weekly wage at the time of injury. The average weekly wage shall be determined by computing the total wages paid in the highest paid 39 weeks of the 52 weeks immediately preceding the date of injury, and dividing by 39.

  (3) If the employee worked less than 39 weeks in the employment in which the employee was injured, the average weekly wage shall be based upon the total wages earned by the employee divided by the total number of weeks actually worked. For purposes of this subsection, only those weeks in which work is performed shall be considered in computing the total wages earned and the number of weeks actually worked.

  (4) If an employee sustains a compensable injury before completing his or her first work week, the average weekly wage shall be calculated by determining the number of hours of work per week contracted for by that employee multiplied by the employee’s hourly rate, or the weekly salary contracted for by the employee.

  (5) If the hourly earning of the employee cannot be ascertained, or if the pay has not been designated for the work required, the wage, for the purpose of calculating compensation, shall be taken to be the usual wage for similar services if the services are rendered by paid employees.

  (6) If there are special circumstances under which the average weekly wage cannot justly be determined by applying subsections (2) to (5), an average weekly wage may be computed by dividing the aggregate earnings during the year before the injury by the number of days when work was performed and multiplying that daily wage by the number of working days customary in the employment, but not less than 5.

  (7) The average weekly wage as determined under this section shall be rounded to the nearest dollar.