Paragraph 3
The net contribution shall be a sum equal to 82 ½ per cent of the gross contribution, except that—
(a)
where the gross contribution does not exceed £4 every four weeks and the said sum is not a multiple of one halfpenny, the said sum shall be rounded off to the nearer halfpenny, or, if the said sum is a multiple of one half of one halfpenny, to the nearer penny, and
(b)
where the gross contribution exceeds £4 every four weeks and the said sum is not a multiple of one penny, the said sum shall be rounded off to the nearer penny, or, if the said sum is a multiple of one halfpenny, to the nearer even penny.