Number Of Members: 8/10 Even though your forum is old, 355 members is a good amount. Only bad thing is that you should try to get more members because you haven't had a new member in days and you are very close to your goal so advertise more, and get other's you know to join if they haven't already. Other than that your member count is very well.
Number Of Active Members: 5/10 221 of your 355 members have either 0 or 1 post on your forum. You should create something to keep your members on your forum like an arcade or more contests. Basically, just get them to post more.
Number Of Posts (Spam or Otherwise): 6/10 your forum has been open since 2006 and only has a little over 10,000 posts.You should advertise more and again like a said above, get more of your members to post. Post exchanges are good to get the posts going, but too many of them will cause a lot of inactive members so I wouldn't suggest doing too many post exchanges. But 10,000 posts is still a good amount of posts, it could be a lot better.
Appearance (First Impressions): 8/10 I have always liked the phpbb skins where the background is black with the different color border around it. I don't like purple too much but it is nice. Your banner matches and looks like it was made specifically for that skin. I'd recommend making more skins and making more selections for your members to choose from though, because more skins fits more of your member's wants.
Layout: 15/20 Your layout is easy to navigate, and your categories and forums are in good order with general discussion at the bottom and announcements at the top. The reason I gave it a 15/20 though is because it is a rather basic and boring layout. Your forum have the typical layout of a phpbb forum. You should see about sub-forums, and ask your members if they'd like a portal. A portal will help you organize information better and will spice up your layout better so it's not just "Go to forum index, go to forum and post.
Moderation: 7/10 I see you have plenty of admins. At first I was going to say more than you need but I saw how many people you have had banned so I figured the admins were necessary. You also have plenty of moderators and since your ban list is so big, I would say all of your staff is needed. On a regular forum I would say they have too many staff members but yours is for a good reason.
Activity:(marked out of 10) 7/10 Most of your forums have been posted in this month by your members and staff so your members and staff post often. Like I said in some of the above ratings, get more members to join and be active and get some of your regular members to post more. Try to get as many of your regular members to post though, and it'll put an ease on you trying to get new members as they will want to join as they see your current members are making good discussion.
spelling and grammar 10/10 you and your staff use proper grammar, punctuation and spelling. If you mess up a few things, we are just human and will make mistakes so I don't count mess ups unless you do it often. Other than that good job.
Overall Mark : 60/100 You need to get your current members active, and get new members. More skins would be much appreciated by your members, and more things to do such as contests with prizes, and whatnot. A better layout will help to, as yours is rather boring (Not pun intended there, just friendly criticism). Boost activity, and a new layout will set you higher!. Good luck