I would guesstimate this question has been triggered by the man seeing visible contention on his cable at peak times.
The answer I would probably give, beyond a simple figure, is that it's as much as the ISP says it is, and they should accordingly scale their network to accommodate it while supplying a reasonable level of performance.
I tend to consider reasonable as being that a customer should either never or almost never experience speeds equal to those of the tier below.
Here's mine for the past 3 months. The heavy month was due to the ISP counting uploads and downloads, and our downloading and uploading for someone who was about to travel around the world for a year and wanted to get her content together and then all in one place on the cloud
