The report also offered a window onto how the government is using information about Americans that it incidentally sweeps up without a warrant because the foreigners were talking with or about an American. The practice has been the focus of recurring debates about privacy and security.

In 2018, the report said, analysts queried material harvested from that program for information about an American 14,374 times. That was a continued decline, down from 16,924 in 2017 and 30,355 a year earlier. Those numbers referred to searches of metadata — logs showing who contacted whom, but not what they said.

The report also said F.B.I. agents opened no ordinary criminal investigations into Americans, as opposed to national security inquiries, based on Section 702 data last year. Nor did they scrutinize any information from 702 data that came up in response to queries for an American’s information when agents were working on a criminal case with no connection to foreign intelligence.

But the report did not say how many times the bureau did either of those things when agents did deem their work to have a national security link.

Because the future of the Freedom Act system for accessing logs of Americans’ phone calls and texts is in question, some of the most notable statistics concerned its use. Analysts use the system to scrutinize patterns of messages — both whom a target has contacted, and whom those contacts have in turn communicated with — to hunt for hidden associates of terrorism suspects.

In May 2018, after discovering that the Freedom Act system was sweeping up some phone and text records that the N.S.A. had no lawful basis to receive, the agency deleted hundreds of millions of logs it had gathered since 2015 and started over. It has cited technical reasons for sweeping up the information but has not fully explained them.

Earlier this year, a senior Republican congressional aide said that the N.S.A. had not been using it for months, suggesting that it has continued to cause technical headaches and raising the question of whether the Trump administration will ask Congress to extend the Freedom Act or let it expire. The N.S.A. declined to comment about that portrayal, and the report did not address the system’s status.