I don't have that information, and I perhaps was a little too strong in my phrasing. Nevertheless, if you're not confident that you fall at an E5 level when joining, there's a chance you'll come in at E4, which is not necessarily a bad thing. E5 is a terminal level for engineers, in the sense that you can stay there for the rest of your career at Facebook. If you spend too long at E4 without promoting, you may be fired.