User Role Plugin

Does anyone know if there is a plugin that can automatically change a user’s role once they post a certain amount of posts? I have a website where, by default, a user is registered as a contributor, but once they posts 10 posts I change them to an author. I now have over 500 registered users and going in over and over to change the roles is rather annoying, not to mention monotonous.

Is there a plugin that can do this for me?
Thanks in advance.