13.—(1) The proportions of male and female full-pay relevant employees in the lower, lower middle, upper middle and upper quartile pay bands is to be determined as follows.

Step 1

Determine the hourly rate of pay for each male and female full-pay relevant employee and then rank those employees in order from lowest paid to highest paid.

Step 2

Divide the employees, as ranked under Step 1, into four sections, each comprising (so far as possible) an equal number of employees, to determine the lower, lower middle, upper middle and upper quartile pay bands.

Step 3

The proportion of male full-pay relevant employees within each quartile pay band must be expressed as a percentage of the full-pay relevant employees within that band as follows—

where—

A is the number of male full-pay relevant employees in a quartile pay band; and

B is the number of full-pay relevant employees in that quartile pay band.

Step 4

The proportion of female full-pay relevant employees within each quartile pay band must be expressed as a percentage of the full-pay relevant employees within that band as follows—

where—

A is the number of female full-pay relevant employees in a quartile pay band; and

B is the number of full-pay relevant employees in that quartile pay band.

(2) Where employees receiving the same hourly rate of pay fall within more than one quartile pay band, the employer must (so far as possible) ensure that, when ranking the employees under Step 1, the relative proportion of male and female employees receiving that rate of pay is the same in each of those pay bands.