This new source is called the I-92. Look here to understand what is behind this source.
I-92 data are obtained electronically from U.S. and foreign flag carriers operating international arrival or departure flights to and from the United States (Canada is included as of 2011). The Department of Homeland Security – Customs and Border Protection’s Advance Passenger Information System (APIS) based “I-92” system provides air traffic data on the following parameters: number of passengers, by country, airport, scheduled or chartered, U.S. Flag, foreign flag, citizens, and non-citizens.
