Where can I find statistics that show how much data home internet connections generally use in a month?

I would like data in the form of a frequency distribution, showing the range of usage from very low to very high.  This would provide context for comments like "I use only 30 GB/month" or "a 200 MB/month plan is of no use to anyone".  30 GB/month seems like a lot to me - but is it average, or in the top 10%, or the top 1%, or what?

If there is no published data available, perhaps a representative from an ISP could provide some enlightenment?

Thanks,

Bob.