U.S. airlines carried 58.4 million passengers in September 2021 (preliminary), compared to 25.1 million passengers in September 2020 according to data filed with the Bureau of Transportation Statistics (BTS) by 20 airlines that carry more than 90% of passengers. The 133% increase was the smallest year-over-year growth since March (see Figure 2). September 2021’s tally of 58.4 million passengers is down 19.5% from pre-pandemic September 2019’s 72.6 million.