9.—(1) For the purposes of paragraphs 2 (calculation of earnings) and 5 (calculation of earnings of employed earners) the earnings of an individual derived from employment as an employed earner to be taken into account are, subject to sub-paragraphs (2) and (3), their net earnings.
(2) There is disregarded or deducted as appropriate from an individual’s net earnings—
(a)any sum, where applicable, specified in paragraph 14 (sums to be disregarded in the calculation of earnings), and
(b)any care charges to which paragraph 15 (care charges to be deducted in the calculation of earnings) applies up to a maximum deduction, in respect of such care charges incurred by any individual, of 50% of their net earnings less those sums, if any, specified in paragraph 14 which are disregarded.
(3) For the purposes of sub-paragraph (1) net earnings are calculated by taking into account the gross earnings of the individual from that employment, less—
(a)any amount deducted by way of—
(i)income tax,
(ii)primary Class 1 contributions under the 1992 Act, and
(b)one half of any sum paid by the individual in respect of a pay period by way of a contribution towards an occupational or personal pension scheme.