"I'm not even sure if they've moved in the rankings at all in the past couple years since the 3rd tier isn't ranked individually."
We were in the second tier last year. Currently, we are at the top of the third tier. As you mentioned, the third tier schools are not ranked, however, the individual schools receive notice as to how they were ranked. Our Dean held a meeting after the new rankings were published and informed the student body of our ranking, why we dropped, and what they are doing to help the school climb back into the second tier.