771R29. Subject to section 771R30, the proportion that the business carried on in Québec is of the aggregate of that carried on in Canada by a railway corporation is one-half the aggregate of(a) the proportion that the number of equated track-kilometres of the corporation in Québec is of the number of equated track-kilometres of the corporation in Canada; and
(b) the proportion that the gross ton kilometres of the corporation in Québec is of the number of gross ton kilometres of the corporation in Canada.