• the pay that you pay pension contributions on in the twelve months up to the date you leave or retire; or

• either of the two years before your last twelve months if your pay was higher then.

If you work part-time it's the pay you would've got if you worked full time.

Also, if your pay goes down in the last ten years of your membership you may be able to have your pension worked out on an average of three consecutive years in the last ten years of your membership.