I am trying to predict first term GPA for college students based on a number of incoming factors (high school gpa, placement test, year). This isn't the overall model just a simpler one. The first term GPAs are on the interval 0 to 4, however the predictions from the linear OLS model (i'm using sklearn) never go above 3.6 (see picture). Is this some sort of gotcha that I am missing? There are certainly data in the training set with first term GPA that is between 3.6 and 4.0. I didn't expect perfect performance but this is odd to me.
[![enter image description here][1]][1]

[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/gXKz2.png
  [2]: https://i.sstatic.net/ZnsDS.png