Office 365 Expert - I am not. I have a customer that...

I have a customer that heavily uses Microsoft Office 365. It's hosted. All the data I see about usage per user appears theoretical. In that the formulas assume people are taking turns using the bandwidth as if there is a patient line of packets at the Internet gas pump. Nobody is clicking at the same time. We all know that is not the real world. Does anyone have any experience with Office 365 hosted that can tell me the practical bandwidth allocation (NOT in KB per month, but in megabits/sec) for 100 users (during normal work hours) needs to be available ? Thank You in advance, Bob Evans CTO Fiber Internet Center