From the introduction: "The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) National Tracing Center (NTC) is the nation's only crime gun tracing facility. As such, the NTC provides critical information that helps domestic and international law enforcement agencies solve firearms crimes, detect firearms trafficking and identify trends with respect to intrastate, interstate and international movement of crime guns. For calendar year (CY) 2011, the NTC traced more than 319,000 firearms; for CY 2012, more than 332,000 firearms; for CY 2013, more than 336,000 firearms; for CY 2014, more than 351,000 firearms; for CY 2015, more than 364,000 firearms; and for CY 2016, more than 364,000 firearms. Over this time period, the NTC has traced firearms for the United States and 129 other countries. [...] This report relates only to firearms recovered in the top five reporting Caribbean nations and traced by ATF. The firearm trace results are based upon the supplied firearm identifiers on the Caribbean trace requests. The Caribbean trace data in this report is organized by the calendar year in which the firearm was recovered, not the year in which the trace was initiated. For example, if a firearm was recovered in 2016 but the trace was not initiated until 2017, the data will be organized in the year of recovery, 2016. Organization by recovery date provides valuable investigative leads as well as more specific trend data."
United States. Bureau of Alcohol, Tobacco, and Firearms: https://www.atf.gov/