Remaining Shulker Counter in End Cities

I've spent lots of time flying/building around End Cities to ensure I've cleared out all the alive shulkers with no knowing if I have killed them all or not.

A feature, similar to the counter of remaining raiders in a village raid would be useful in showing players how many Shulkers remain within an End City.

Raider counter that is at the top of the screen during a raid.

Proposed overlay when in an End City with Shulkers remaining.