Per the airport's passengers, are they per day, or per year? Chicago Ohare, I can't believe 71 million people go through each day, so that has to be yearly, right? Is that count ONLY for the outgoing passengers, or the return trip as well? So, how do we figure what plane(s) to best use? Could I figure, for example, a 10 seater plane to/from would do 20 people. Multiply that flight by 24 days, multiply that by 365 days. Gets you = 175,200. Is that right? A 10 seater plane could theoretically service a 175,000 airport? If that is so, then a 100 seater airplane would have seats left open, as it would service 1,752,000 passengers per year? Please be detailed in your answers/responses, and show any math you may use. I really would like a educated answer, instead of guessing. Thank you.