Yes, for sure.
First of all, we differentiate between those charges that we charge as an airline, which go straight into the airline.... These are what we call air transportation charges. They include the base fare and this YQI surcharge that you mentioned, and then the others are third party charges that come on top of it.
Why do we have a YQI surcharge? It's because there are infrastructure costs embedded in our base fare. For instance, navigation charges—those are domestic—are, I think, $15 per passenger. They're part of what the airline has to pay, and they're not a flow-through that goes through the other taxes and fees. This is reflected in there, and the same is also true for the aeronautical charges that we pay to airports.
It's basically a reflection of infrastructure costs that are paid by the airline and not paid through the tax box of the passenger.