In 1921 how many air routes served New York and Chicago

In 1921, there were air routes linking some important cities in the United States, at the time, airplanes weren't in condition of carring more than 16 passengers, and had to refuel more often than now, New York had 2 routes, one to Washington DC, which made a stop in Philadelphia to refuel and another to Chicago, with stops in Cleveland and Pittsburgh for being a longer distance, in the case of Chicago, there were 4 routes, one to New York that had the same stops in Cleveland and Pittsburgh, another to San Francisco that made 10 stops before arriving, being several of them: Cheyenne, Salt lake city and sacrament, another route was to St Louis, and the fourth one to Minneapolis.