2.—(1) Subject to sub-paragraphs (2) to (4)—
(a)where a person is paid weekly, the amount of those earnings shall be determined by aggregating the amounts received in the 5 weeks ending with the relevant week and dividing by 5;
(b)where a person is paid monthly, the amount of those earnings shall be determined by aggregating the amounts received in the 2 months ending with the relevant week, multiplying the aggregate by 6 and dividing by 52;
(c)where a person is paid by reference to some other period, the amount of those earnings shall be determined by aggregating the amounts received in the 3 months ending with the relevant week, multiplying the aggregate by 4 and dividing by 52.
(2) Where a person’s earnings include a bonus or commission which is paid during the period of 52 weeks ending with the relevant week and is paid separately from, or, in relation to a longer period than, the other earnings with which it is paid, the amount of that bonus or commission shall be determined by aggregating such payments received in the 52 weeks ending with the relevant week and dividing by 52.
(3) Subject to sub-paragraph (4), the amount of any earnings of a student shall be determined by aggregating the amount received in the year ending with the relevant week and dividing by 52 or, where the person in question has been a student for less than a year, by aggregating the amount received in the period starting with his becoming a student and ending with the relevant week and dividing by the number of complete weeks in that period.
(4) Where a calculation would, but for this sub-paragraph, produce an amount which, in the opinion of the child support officer, does not accurately reflect the normal amount of the earnings of the person in question, such earnings, or any part of them, shall be calculated by reference to such other period as may, in the particular case, enable the normal weekly earnings of that person to be determined more accurately and for this purpose the child support officer shall have regard to—
(a)the earnings received, or due to be received, from any employment in which the person in question is engaged, has been engaged or is due to be engaged;
(b)the duration and pattern, or the expected duration and pattern, of any employment of that person.