The original source from which this data is pulled is updated at 9AM ET daily. This HASH repository is updated less frequently. The dataset published on HASH includes additional calculations showing the YoY percentage-based decline in daily throughput.
2020 and 2021 checkpoint travel numbers compare to prior year/same weekday data.
Data may be periodically adjusted to include Known Crewmembers and later flight travel numbers. More information and coronavirus related US travel news can be found on the TSA website.