U.S. Border Patrol Southwest Border Family Unit and UAC Apprehensions (FY 2016 - FY 2017) [open pdf - 52KB]
This document from the United States Border Patrol contains data on the apprehensions for Family Units, defined as the number of individuals apprehended with a family member by the U.S. Border Patrol, and Unaccompanied Alien Children (0-17) in Fiscal Year 2017 through January. The document then compares these numbers to same time period from the previous year. The data is pulled from all sectors on the southwest border and contains the citizenships of those apprehended.
U.S. Customs and Border Protection: https://www.cbp.gov/