Deduction under Section 80C: tiered formula introduced for computing allowable deduction and increased prescribed limits in subsection four. The amendment substitutes subsection (1) of Section 80C with a tiered deduction formula tied to the aggregate of sums in subsection (2): where the aggregate does not exceed Rs. 1,000 the whole is deductible; where it exceeds Rs. 1,000 but does not exceed Rs. 5,000 the deduction is Rs. 1,000 plus 50% of the excess over Rs. 1,000; where it exceeds Rs. 5,000 the deduction is Rs. 3,000 plus 40% of the excess over Rs. 5,000. It also replaces references to fifteen thousand rupees with twenty thousand rupees in subsection (4) clauses (ii) and (iv).