Section 80C deduction formula revised to a tiered percentage-based computation tied to aggregate eligible sums. Amendment substitutes subsection (1) of Section 80C with a tiered computation for deduction: full deduction where aggregate does not exceed Rs. 5,000; Rs. 5,000 plus 35% of the excess where aggregate exceeds Rs. 5,000 but does not exceed Rs. 10,000; and Rs. 6,750 plus 20% of the excess where aggregate exceeds Rs. 10,000, to be applied in computing total income subject to the section's provisions.