Annuity deposit rates set sliding percentages with capped deposits across income bands to determine mandatory contributions. Annuity deposit obligations are prescribed by income bands with progressive percentage rates on adjusted total income and ceilings that limit deposits to the aggregate of (a) a percentage applied to income within prior bands and (b) one half of the excess over the band threshold. 'Total income' is defined as income computed under the Income tax Act without allowance under section 280O.