21. In computing the average costs contemplated in sections 14 and 17, no account shall be taken of the costs imputable to the transportation of pupils.
In computing the grants contemplated in sections 14 and 17, however, no account shall be taken of pupils for whom a school corporation assumes the tuition fees under section 450 of the Education Act (chapter I-14) or of pupils who are the object of a contract for service contemplated in section 67 of this act or of pupils registered for a self-improvement course.