(1) For the purposes of this Act, the monthly earnings of an employee shall be computed in the manner that is best calculated to give the rate per month at which the employee was being remunerated during the previous twelve months if the employee has been so long employed by the same employer, but, if not, then for a shorter period during which the employee has been in the employment of the same employer.
(2) Where by reason of the shortness of the time during which the employee has been in the employment of the employer, or the casual nature of the employment, or the terms of the employment, it is impracticable at the date of the accident to compute the rate of remuneration, consideration may be given to the average monthly amount which, during the twelve months previous to the accident, was being earned by a person of similar earning capacity in the same grade employed at the same work by the same employer, or, if there is a person who is not so employed, by a person of similar earning capacity in the same grade employed in the same class of employment and in the same district.
(3) For the purposes of subsection (1), employment by the same employer means employment by the same employer in the grade in which the employee was employed at the time of the accident, uninterrupted by absence from work due to illness or any other unavoidable cause.
(4) Where the employee had entered into concurrent contracts of service with two or more employers under which the employee worked at one time for one employer and at another time for another employer, the monthly earnings shall be computed as if the earnings under those contracts were earnings in the employment of the employer for whom the employee was working at the time of the accident.
(5) The earnings of the employee under the concurrent contract shall be disclosed to any other employee at the time of engagement with the latter and shall be taken into account only so far as the employee is incapacitated from performing the concurrent contract.
(6) On the request of the employee to the employer liable to pay compensation, that employer shall furnish in writing a list of the earnings which have been earned by that employee on which the amount of the monthly earnings may be calculated for the purposes of this section.