b. The ability of a volunteer firefighter to perform on a five-day or six-day basis either the work usually and ordinarily performed by him or her in the practice of his or her profession or in the conduct of his or her trade or business, including farming, and from which he or she could derive earned income or other work which for any such person would be a reasonable substitute for the profession, trade or business in which he or she was engaged at the time of his or her injury.
Every volunteer firefighter shall be considered to have earning capacity and, if the provisions of paragraphs a and b above are not applicable in any given case, the workers' compensation board, in the interest of justice, shall determine the reasonable earning capacity of the volunteer firefighter with due regard to the provisions of such paragraphs and the work he or she reasonably could be expected to obtain and for which he or she is qualified by age, education, training and experience. The ability of a volunteer firefighter to perform the duties of a volunteer firefighter, or to engage in activities incidental thereto, may be considered in determining loss of earning capacity, but the inability of a volunteer firefighter to perform such duties or to engage in such activities shall not be a basis of determining loss of earning capacity.