I'm not sure that number is accurate. It doesn't burn one DEC per transaction. It burns one DEC per new listing. So if a card gets listed or changes it's price, there is a charge. If it just sits on the market at the same price and gets rented over and over again, there is no fee. So, in this situation, I would imagine a very large percentage of those transactions are cards that just sit at the .1 DEC price (or lower) and never move.

I'm not sure where you can find the ones that actually have a fee charged but...that's the number to look at.

In the meantime, the supply of DEC is no longer the issue. That is going to be taken care of shortly with the onset of Land surveying and staking of cards. This was done because there were getting to be way too many transactions and it was bogging down the servers and costing the team way too much to maintain them. We'll have to see how much of a difference this makes to that element of the equation.