How to get into the Iowa Writer's Workshop?

What kind of GPA do you need? Do you need something super special to set you apart from everyone else? I know that they only take a super small percentage of applicants. I have the basics down (a good GPA and talent), but I don’t know if that will be enough to ensure an acceptance. Any help or knowledge of how the school determines who they admit would be extremely helpful. I’m going into my junior year of college now so I have some time to beef up my application. Thank you so much for your time!