Any suggestions as to the best way to tackle this? I have some code written to calculate some of the other metrics that I need (below) but I haven't written anything for the 5 min calculations since I'm at a loss as to where I should start.

So am I! Looking at the table, I'd see 1 request in the period 13:00 - 13:05, 1 request in the period 13:05 - 13:10, and 2 requests in the period 13:10 - 13:15. I've no idea which calculation you use to get a 2-2 split.