Statistically speaking, how many projects end up being 'death march' projects, and how many end up being successes? When looking at one person's experiences, i

Statistically speaking, how many projects end up being 'death march' projects, and how many end up being successes? When looking at one person's experiences, it's possible that she might have nothing but 'failures'. Whereas the next person's experiences might be nothing but 'successes'. Though I would venture to say that the average experience is to have some failures and some successes.