Pretty sure anybody that buys membership will be able to get a ticket now.
33,411 - 21,000 ST holders = 12,411
12,411 - 2,411 non-ST membership owners (pure guess but would it really be higher?) = 10,000
Is there really going to be 10,000 people who spend the extra £25 to guarantee the ticket? I'd imagine it'll go down to non-ST/membership holders quite comfortably, unless I'm greatly underestimating the amount of people with a membership.