On this page is a table of airport data. Each airport has data and a link to more information about that airport. The table includes information about 'enplanements', which the FAA defines as the number of commercial passengers boarding an aircraft at an airport. This number does not include arriving or through passengers, so the number of 'flights' in and out of an aiport would be about double that number. That number includes only 'for hire' traffic, so it should be a pretty good gauge of commercial traffic as opposed to private traffic. There is also a number for 'rank', which is the rank of the airport based on the enplanement information.