According to Wasserman [Wasserman, N., The Founder's Dilemmas: Anticipating and Avoiding the Pitfalls That Can Sink a Startup, Princeton, NJ: Princeton University Press, 2012], only 4% of startups have a CFO on board at the start. 70% of “mature” startups have a CFO.
Related Question:
How common is it to have a vice president of sales? Marketing?