May not be percentage rate but it would seem that the entire Big Ten has fabulous numbers if there is the indication that 970 out of 1000 (97% roughly?) are completing their college years successfully, whether or not graduating, that has got to be far above the same number of the student body in general or as compared to non-athletes.
All things considered, the student athletes have significant advantages over the non athletes and should do better (free or dirt cheap cost means less work demands), typical 5 years to get a 4 year degree, many assistance and tutoring, etc programs and so on. But, it is quite remarkable nonetheless.
I would suspect that NU numbers may be somewhat lower due to the abnormally high numbers of transfers which may follow with a coaching change so it might be interesting to compare NU to other programs with a similar coaching change as opposed to just all schools. I assume that players leaving for another school will be a negative impact on the 'score' calculations. However, all those things being considered, I would of course like to think the number should return to a near the top of the country range in the next couple years, IF the department is putting its full efforts into academic and athletic success as has been the historical norm for NU.