I'm interested in air traffic density and flux (i.e., traffic that enters and exits) for the ZLA airspace. A good first pass would be flights that begin or end in ZLA (and that data is pretty easy to get from somewhere like OpenFlights, but that doesn't include routes like PHX-SEA, where a flight would pass through ZLA on its way from ZAB to ZSE. Is there any public information available about what routes pass through ZLA?
(Actually, I'm much more interested in the air traffic density and flux specifically for the Los Angeles metropolitan area, but I figure starting at the area control center level might be a good place to start.)