Do the average GPAs that colleges report include senior year?

I recently visited Northeastern University, and on the handouts they gave us it said that the GPA of the middle 50% of admitted students was between 3.7 and 4.2 on a 5 point scale. That surprised me, since my own GPA is a 3.67 heading into senior year and I considered myself a solid applicant. I've taken 4 APs over the course of my high school career, but even if I had gotten A's in every single class I'd taken in high school, my GPA would only be a 4.19.

This got me wondering how accurate the GPAs that colleges report are, and whether they include senior year. I plan on taking 4 more APs as a senior, which will definitely boost my GPA. So the question is, do the average GPAs of admitted students that colleges report include the senior years of high schoolers?