That doesn't make sense; There isn't one pool of "upload" data and another of "download" data. Rather, there is one pool of data streaming from edges into the core (upload) and back out again (download). You can either attribute each chunk of data to its uploader or to its downloader, but in either case, the pool is the same size.

Edit: or these metrics don't mean what I think they mean, in which case, please tell me!