These values are (I suppose) in bytes over a minute period. Normally, most people want to know about speed in Mbps, so I was initially multiplying that value by 8 (bytes ->bits) and then dividing by 60 (minute -> seconds).
It did make sense to me, but rapidly I found out there was a problem with it: when data started being aggregated, values stopped making sense.
So, I then did what makes even more sense: use the rate transformation, with the ":rate(s)" syntax, and multiplying by 8. Now everything seems much more correct.
Now, well I'm confident that this is the correct way to do it, I would like to ask the opinion of others working with SNMP, to get a sense if someone is doing it in a better way?