Iowa is so high because there are only 3 public 4-year schools in the state and over 30 private 4-year schools. When you take the average by school instead of by student, that means that the more expensive private schools are going to drive the average.

This is also why the in-state and out-of-state are so close as most of the private schools probably do not have an in-state discount.

(Oregon has 7 public schools to 21 private. Vermont has 5 public schools to 11 private, but 4 of the public are considered a single system and so it might only be a 2 public schools for the purpose of this data source, even though all 4 have separate Title IV listings.)