Under "Unanswered", it shows 0 questions are unanswered, so shouldn't it be 100%? Are you using other numbers I've missed?
The stats and the Unanswered query can at any point in time be lagged, one or the other could be out of date. As I loaded the Unanswered just now, there were 2 questions on it showing with zero answers. By the time I clicked through to one of them, it had an answer.
It's just how the internet works: http://www.google.com/search?hl=en&q=eventual+consistency