I have a somewhat limited sample but it definitely varies a loooot. But if I were to guess I'd say in average they may have 2, 6, 10. It really depends on your background, whether you were at FANG before or your previous YoE are from outside the US or like that.
I think looking at average time to be promoted is a better indicator, and for that we do have stats, the median is around 2, 3 and 4 years.
@nocomp, thanks for your post about median promo times. Just to clarify, median is 2 yrs for L3 -> L4, 3 for L4 -> L5, and 4 yrs for L5 -> L6? What about L6 -> L7? Also, this is stats for the people who got promoted, right? So someone who stays at L5 forever isn’t included?