In-state wasn’t the only comparison listed. For example, half the employed CSU grads were employed at companies located within a few miles from the college. The vast majority of CSU grads were located within the county. The overwhelming portion of companies attending career fairs and other campus events were local . This leads to there being a strong local alumni network. Many kids attending CSU prefer to stay local, which often contributes to why they initially chose to attend a CSU instead of an out of area college.
Brown differs in all of these measures.
I have worked for small companies in the general area as the CSU throughout my career. To my knowledge, none of the companies I have worked for have recruited or attended campus events at any college located more than a 3 hour drive in the past 20 years. As such, it’s not surprising that we don’t have many (any?) employees who attended Brown or colleges in that general northeast region.