No, it means that if their GPA range is 3.1-3.9, then approximately 10% of their matriculating students were below a 3.1, and subsequently 10% of the matriculating students are above 3.9. In other words, if you're not in that range (ie: you're lower than it), then you'd better have a really amazing story and have a lot of other things to make up the deficiency.....and even then, it's a long shot.
It's just a great way to gauge how competitive you would be in their applicant pool.