In Afghanistan, DTM employs the Baseline Mobility Assessment tool, designed to track mobility, determine the population sizes and locations of forcibly displaced people, reasons for displacement, places of origin, displacement locations and times of displacement, including basic demographics, as well as vulnerabilities and priority needs. Data is collected at the settlement level, through key informant interviews, focus group discussions, and direct observations. Through the Baseline Mobility Assessments, DTM tracks the locations, population sizes, and cross-sectoral needs of five core target population categories: Returnees from abroad, out-migrants (Internally Displaced Persons, or IDPs), subdivided in "arrival IDPs", "returnee IDPs", and "fled IDPs". Between January and March 2018, 15 provinces, 188 districts and 6,744 settlements were assessed, including interviews with 36,807 key informants. Between 2012 and 2018, 1,810,954 returnees and 1,843,833 IDPs currently in host communities, were identified.