Asking for a raise

Hi all,

I'm looking for some advice on asking for a raise. I will soon complete 1 year in my current position. In all of my previous jobs there was a very structured and formal review process, with salary increases directly tied to your performance rating. Increases had nothing to do with revenue generation, and there was no room for negotiation. No such process exists where I am now. I'm in a private practice, and everything is at the discretion of the sole physician practice owner. I have no idea how much of an increase I should be asking for. I know how much revenue I've generated, but I don't know what the overhead is, or any other costs I need to take into account. I know he is very pleased with my performance, so that should not be an issue.

I am the only NP in the practice. I am being paid well and my salary is in line with the local market. I'd be interested to hear what others have to say.

Thanks.