I think these are very generic statistics determined by some sort of unknown logic:
The column after the
Pages/v which I assume is "Pages Per Visit (average).
The low/medium/high activity titles are probably determined by the number of pages a visitor browses in one session. This is where the "unknown logic" comes in. These numbers likely mean that there were "xyz" visitors who visited more than
high logic pages, "rst" visitors who saw between
low and high logic and then "abc" visitors who went to fewer than
In fact, I'm almost certain of that. If you look into the company or software that generates those statistics, perhaps they will provide information as to exactly what "High, Med, and Low" activities are.
Maybe beyond number of pages visited, it accounts for time spent on pages as well.