Captive Portal

I got 100 tickets in a roll, I see the status used is 13 and ready is 87.
I copy the ticket no 14 and test voucher, it told me this ticket already been used. I check all the 14 tickets found all has been used, but why the status shown 13 used? Maybe the system miss out one ticket i think.
How can i modify manually the used and ready number to the correct status in order to avoid mis-taken?