Gujarat Land Revenue Code, 1879
(1) Notwithstanding anything contained in this Chapter, it shall be lawful for the State Government in any year, after the expiry of every ten years from the date on which the settlement was introduced under section 117O, to enhance or reduce the assessment on lands in any zone, by placing a surcharge, or granting a rebate, on the assessment by reference to the alteration of the prices of the principal crops in such zone. (2) For the purpose of sub-section (1), the prices of principal crops shall be recorded and published in the Official Gazette. (3) The surcharge shall be levied or the rebate shall be granted under sub-section (1) according to the scale prescribed by rules made in this behalf.]