The only way for the quantity of bitcoin to go down is if many of the bitcoins owned become unaccessible by their owners. If they loose the private keys for their coins those coins will no longer be moved. As for the protocol it will ever bethe same no matter what, so only 21 million coins will be ever produced
Have you guys read front page of the thread, I think the OP question already answered and consider solved.
The exchanges 'Bleutrade' seems strange which charge fees to balance that stored so the quantity go down (not bitcoin in circulation he mean)