This doesn't really make sense.  Isn't that the point of season tickets - that they give you a fixed number for the whole season?
Not that I am not on your side here on this thread, but if that statement is true then maybe they shouldn't be called season ticket holders.
That's why the disclaimer is "Number of Season Ticket Holders 
(as of the beginning of the season) : 4128"
Gives you a rough idea of where they stand.
I think there's more to it than that, honestly, but there is a behind the scenes variable.
 
                                
                                
                                
                                
                                
                                
                                    NO ONE at this table ordered a rum & Coke 
 Charles: Penn has some good people 
 A CT? Really? 
 Any two will do 
 Any three for me 
 Any four will score 
 Any five are live