Statistical Transparency Report Regarding Use of National Security Authorities: Calendar Year 2016 [open pdf - 1MB]
"In June 2014, the Director of National Intelligence (DNI) began releasing statistics relating to the use of critical national security authorities, including the Foreign Intelligence Surveillance Act (FISA), in an annual report called the 'Statistical Transparency Report Regarding Use of National Security Authorities' (hereafter the 'Annual Statistical Transparency Report'). Subsequent 'Annual Statistical Transparency Reports' were released in 2015 and 2016. [...] This fourth report has been reformatted to provide a description of the statistics being reported. Related definitions and additional context to the statistics included in this report are provided throughout. The order in which the statistics are presented remains consistent with last year's report and follows the order set forth in 50 U.S.C. § 1873(b)."
Office of the Director of National Intelligence: http://www.dni.gov/