Math equation for loosening space on carousel animation?

I have a carousel animation (you know, the ever popular rotating icons that is so ubiquitous now-a-days) and I'm wondering if anyone who is familiar with this type of thing (and brilliant at math!) could suggest a way that I can have the rotating objects spread out more when they're in the back half of the circular path, so that more than half of the objects stay in the front half as the rotation continues. I have them so that they're invisible in the back half, so anything they do back there is fine, so long as more than half are in the front half. Thank you very much for your help in advance!