In estimating the proportion of the cost to be borne and paid by each adjoining owner for or in respect of –

(a) the construction of any rabbit-proof fence; or

(b) the conversion of any existing fence into a rabbit-proof fence –

under the provisions of this Act, the arbitrators or umpire shall take into consideration the benefit that is likely to accrue to each of such owners by reason of the construction or conversion of such fence.