I am new to FlyerTalk. Have gotten a lot of information from the site.

I can get the CLASS AVAILABILITY, is there a way to know how full is the flight?

Am I right to say that P9 F9 Y9 B9 M9 H9 Q9 V9 L9 T9 K9 is pretty empty.

How emtpy is empty?
Why is 9 the maximum number? I suppose there could be more than 9 seats for each class.

Thanks.