"Between Jan. 1 and Dec. 31, 2020, the agency screened a total of approximately 324 million passengers throughout its airport security checkpoints. That figure represents just 39 percent of the approximately 824 million total passengers screened in 2019," the release said.
The TSA said travel volume bottomed on April 14, 2020 when only 87,500 passengers were screen at security checkpoints throughout the United States - a 96 percent drop over the previous year.
Travel volume rebounded around the time of the major US holidays, including Thanksgiving and Christmas, it added.
The TSA also said it expects passenger traffic to remain below the pre-pandemic levels for most of 2021.
TSA data focuses primarily on air passengers and underscores the difficulties felt by the airline industry amid the severe restrictions imposed amid the coronavirus pandemic.
Last month, the International Air Transport Association (IATA) urged European Union nations and the United Kingdom to end quarantine rules for airline travelers, citing a new series of studies showing restrictions do little to prevent contracting the novel coronavirus.