62. Subject to section 63, the Chief Electoral Officer may grant a supplement to the amount payable for the performance of a contract in any of the following cases:(1) where an amendment to the contract is required to ensure the carrying out of the project;
(2) where there is a variation in the amount to which a percentage already established is to be applied or a variation in a quantity for which a unit price or rate was agreed upon; or
(3) where salaries payable have been changed under an Act or an order in council.