Question: Which city are the headquarters of this airline founded in 1946 and privatized in 1969, which operates joint ventures with Delta Air Lines, located? 
Sentence (from "Delta Air Lines"): The airline along with its subsidiaries and regional affiliates operate over 5,400 flights daily and serve an extensive domestic and international network that includes 319 destinations in 54 countries on six continents, as of October 2016.
Relevant evidence: No