The chances are, I assume, that most of the 'guests' are members who have not logged in.
The most ever thing seems a bit odd though. The number seems to go up and down so can't really me a most ever can it? Incidentally, it now gives the most ever as today at 23:54 - is that today in yesterday's zulu or is it still 3 hours away?
Any idea when search will come back?