(b)in determining the amount of enhancement, the Collector shall have regard to -(i)the increase in the productive powers of the land caused or likely to be caused by the improvement;(ii)[ the cost of making the improvement and the proportion in which such cost was borne by the landholder and by the ryot;] [Substituted by the Madras Estates Land (Amendment) Act, 1934 (Madras Act VIII of 1934).](iii)[] [New sub-clause (iii) was inserted and the original sub-clauses (iii) and (iv) were renumbered as sub-clauses (iv) and (v) respectively, by section 22(i)(b) of the Madras Estates Land (Amendment) Act, 1934 (Madras Act VIII of 1934).] the probable annual cost of maintenance of the improvement -