26. The insurable wages of an auxiliary worker declared in accordance with section 25 are apportioned by the Commission(1) on a prorata basis of the insurable wages declared for each unit that expressly provides for classification in an exceptional unit, when the employer is classified in one or more exceptional units and in several other units;
(2) on a prorata basis of the insurable wages declared for each unit that expressly provides for classification in an exceptional unit, when the employer is classified in several units but cannot be classified in an exceptional unit because none of the employer’s workers carries out work covered by an exceptional unit;
(3) on a prorata basis of the insurable wages declared for each unit that does not expressly provide for classification in an exceptional unit, when the employer is not classified in an exceptional unit.