(a) In the case of individuals who are taxpayers who have earned income subject to preferred rates of twenty thousand dollars ($20,000) or more during the taxable year, in computing the net income subject to regular taxes for said year, there shall not be allowed as deduction such part thereof described in § 30135 of this title, that is attributable to income subject to preferred rates, as established in § 30111 of this title.(b) In order to determine the limitation imposed in subsection (a) of this section, the adjusted gross income (as defined in § 30103 of this title) shall be classified into two income categories:(1) Income subject to preferred rates, and(2) income subject to regular tax(c) The total of deductions allowable for the taxable year under § 30135 of this title shall be prorated between the two categories of income generated during the same taxable year, as described in subsection (b) of this section. In each income category, there shall be allowed as [a] deduction the proportional amount of said deductions for purposes of computing the taxable net income. History —Jan. 31, 2011, No. 1, § 1033.20, retroactive to Jan. 1, 2011; Dec. 10, 2011, No. 232, § 38.