We started with 11. One left in the first year. 3 more failed to graduate after 4-7 years. 5 people got postdocs. Of the 5 with postdocs, 2 left the country (one involuntarily), I left academia to work in the private sector, and one I haven't kept in touch with. So at most, 2 are on the tenure track in the US [1].

This was Rutgers - at Princeton, the ratio would be a bit better, at NJIT it would be worse. Don't even ask about podunk state.

It's a shitty career path. Unless you are fantastically good, don't waste your time.

[1] My adviser told me I could have been on the tenure track if I wanted to. Since I didn't put it to the test by applying for such jobs, I won't claim it as true.