Chapter 6 of Part 2 of the Principal Act is amended by the insertion of the following section after section 38B:

"38BA. Calculation of certain rates of contribution applicable to part years

(1) Subject to subsection (2), this section applies to a contribution payable under any of the following provisions:

(a) section 21(1);

(b) section 26(1);

(c) section 29(1);

(d) section 30F.

(2) This section shall not apply to contributions payable on emoluments to which Chapter 4 of Part 42 of the Act of 1997 applies.

(3) Where, by virtue of any amendment to this Act, a person is required to pay a contribution to which this section applies at different rates, or in different amounts, in two parts of a contribution year, the rate of the contribution payable by the person in respect of the contribution year shall be determined by the following formula -

((A x C) + (B x D)) /12

where -

A is the first rate,

B is the second rate,

C is the number of months (including part months) in the contribution year during which the first rate is effective in relation to the person, and