Section 153. Grounds of abatement of fixed money rent

153. Grounds of abatement of fixed money rent.— The fixed money rent or the bighori, determined under section 151, of an occupancy, an exproprietary of a hereditary tenant shall be liable to abatement on one or more of the following grounds: — (a) that the rent payable by the tenant is substantially greater than the rent calculated at the sanctioned rates appropriate to him; or (b) that the productive power of the land held by the tenant has decreased by any cause beyond the control of the tenant during the currency of the present rent; or (c) in case of fixed money rent, that the area of his holding has been decreased by diluvion, or by the taking up of land for a public purpose, or for a work of public utility.