Question: What is the approximate capacity of passengers per year of the airport that is considered Condor Flugdienst's main base?
Sentence (from "Frankfurt Airport"): Frankfurt Airport (IATA: FRA, ICAO: EDDF) (German: "Flughafen Frankfurt am Main" , also known as "Rhein-Main-Flughafen") is a major international airport located in Frankfurt, the fifth-largest city of Germany and one of the world's leading financial centres.
Relevant evidence: No