Don't know the % but Matt Campbell did it in two! Been reading different threads, so if I seem to bounce around, I apologize. Just sharing my thoughts from different posts.
To those wondering, Matt Campbell isn't going to leave ISU for NU. The culture is wrong, the atmosphere is wrong. Not saying NU is bad, just that it's wrong for him. Campbell is a teacher more than a coach. If you'd like to see what I mean watch this video. The Soul of A Cyclone.
As far as bringing Frost bringing his staff with him from UCF, many successful coaches have done that in the past. In fact, Campbell did it with his staff from Toledo! That's a few steps below UCF, yet he has made it work. In a few years many of those coaches will be HC. And they too, will be more like a teacher than coach.
As far as money goes, Campbell isn't obsessed with it. He doesn't have an agent. And his last raise? He didn't take it, instead he gave it all to his assistants.
I hope Campbell stays at ISU for a long time, yet I am a realist. He's turned down a couple of pro jobs and a couple of college. I think the only jobs he would take right now would have first been Ohio State, thankfully they went a different way, and Michigan, which may happen very soon. Besides that I think he'll stay at ISU even with an uncertain future for the Cyclones...