I'm almost 100% postivie that in the world it is FRA and in the Western Hemisphere it is MIA. A friend who used to work for AA in MIA (and now at DFW) told me, I'm not sure if he was correct. But that list includes charter, cargo, and scheduled. As for scheduled, it is probably JFK in the US. If my memory serves me right, MIA is served by 116 airlines, including 36 US carriers (16 scheduled passenger) and 82 international carriers (41 scheduled passenger).