I think each school is actually required to have the pass rates publicly accessible, so pretty much all schools have the last three years listed somewhere on their website.
Thanks for these rankings... I didn't know they FINALLY ranked OT schools again. Professional school rankings in general need to be taken with a grain of salt - law school is the same, although the last thing I knew, "reputation" only made up 40% of the ranking. Still, that's a lot. It's a self-perpetuating system. Law school deans can only know so much about so many schools, so the well-known schools stay top-ranked and well-known.
Don't necessarily mistrust the rankings based one seemingly large drops, though. Look at the score, not the rank. Each year a large number of schools have the same score and are tied. Look at how this year it drops from rankings of 15 to 21 to 28 to 31 to 36. Schools with scores of 3.5 are tied for #15, and those with 3.2 are tied for #31. Is there really a huge difference in quality, though? Why not have schools at 3.5 tied for 15, those are 3.4 tied at 16, those at 3.3 tied at 17, and those at 3.2 tied at 18?