Currently M2 after 10 years.
E5 - 3 years
E6 - 2 years
M1 - 3 years
M2 - 2 years.

I very lucky, my boss keep promoted and he pull me up with him.
I see some M2 have a lot of people report under them.

I'm lucky cause nobody report under me. Hahaha.
But the bad thing is I report to many ROs.

But I'm excellent in human skills. I can work with the bosses above.
Thus my promotion..