How should I rate myself on a self assessment form?

The options are poor, needs development, satisfactory, exceeds expectations and excellent

Personally I think I do a ‘ good’ job and sometimes in offer to do other peoples work which means I exceed expectations. But I don’t want to look arrogant.

Bear in mind my bonus is used from these forms ( plus from what other people assess me)

I obviously there are always skills I can develop which I’ll select for some statements but I wish there was a ‘ good’ option rather than a satisfactory which makes me sound mediocre.