2. The gross income that a self-employed worker earns from employment is determined by taking the highest of the following amounts:
(1) the business income realized over the 12 months preceding the date of the accident;
(2) the business income realized during the last complete fiscal year preceding the date of the accident;
(3) the average of business income received during the last 3 complete fiscal years preceding the date of the accident, or, if he has been operating the business for less than 3 years, during the last 2 years preceding the date of the accident.
Business income is composed of the total income, fees and commissions that a self-employed worker customarily receives, minus expenses but excluding the portion of depreciation costs of business-related equipment.
The income, fees, commissions and expenses referred to in the second paragraph are those allowable under the taxation legislation applicable to the self-employed.