149.5. Where the by-laws of the cooperative contain provisions for the purposes of the second paragraph of section 149.2, a shareholding workers cooperative which, upon its winding-up, earns a profit on the disposal of its shares may pay into the enhancement reserve a portion of this profit equal to the average proportion of the business done by the cooperative with its members and auxiliary members, if any, during the five fiscal years preceding the year the winding-up was voted.