may I suggest a statistic course? because you are failing at reading graphs 
I know it is statistics, but still according to the other ones I am still right about having the odd rear occasion that it is above 70 players. Also at first when I read the graph I thought that it's how many different (different IPs and accounts) players have logged in, but I was certain that's not the case because that would probably be around 80-120. Not that I have full access to the server to see myself, but I am sure peak times would be more around 50-70 and at rear occasions up to 80ish during this time of the year. So in which I was currently wrong when I said the players are around 15-60, in my first comment.
@LigH no, that would be a 'LigH troll', an internet troll is someone who is almost like a bot except they are run by a computer, or they just make up dumb crap like; "oh I can see you, I'm that person by your window hahahaha" I'm not arguing I am stating my reply to their replies to my post, got a freakin problem with that?!