The sharp increase from 151 million occurred during the second full year of a new surveillance system established at the spy agency after U.S. lawmakers passed a law in 2015 that sought to limit its ability to collect such records in bulk.

The spike in collection of call records coincided with an increase reported on Friday across other surveillance methods, raising questions from some privacy advocates who are concerned about potential government overreach and intrusion into the lives of U.S. citizens.

The 2017 call records tally remained far less than an estimated billions of records collected per day under the NSA’s old bulk surveillance system, which was exposed by former U.S. intelligence contractor Edward Snowden in 2013.