Success rate for IUI?

I am going to be starting my first IUI at the beginning of June. I will be on 100 mg of clomid. What is the success rate for 1st IUI procedure? My husbands sperm is good, we just have unknown infertility on my part. I have irregular cycles but they can't figure out what is wrong with me. My blood work came back normal and great, just don't ovulate every month, hence no period every month. I just want to know someone elses experiences with an IUI. Thanks!