Dunno, I'm not a pension guru, possibly @vauxhall can advise you or point you in the right direction.Then sadly after 22 years, the rating gets shafted on the pension front. Why is that?
For most ratings the current contract is 12 years, extended to 20 if passed for killick. So far as I'm aware the pension is earnings related.
To be honest, having been on several persion schemes (AFPS 75, RFPS 05 & AFPS 2015) I've yet to see one succeeding another which takes less and pays more, so I imagine the Treasury hold the answer to the query.