From the Document: "According to estimates from the digital publication 'Lawfare', approximately 265,000 people, on average, have left the Northern Triangle region of Central America (composed of El Salvador, Guatemala, and Honduras) in each of the past five years, with the majority bound for the United States. More than twice as many people may leave the region this year, however, as an estimated 508,000 Salvadorans, Guatemalans, and Hondurans left their homes and headed north during the first eight months of FY2019. Although total U.S. apprehensions of unauthorized migrants had been near historic lows in recent years, the arrival at the Southwest border of a growing number of Central American families and children, many of whom are seeking asylum, reportedly has strained the U.S. immigration system. Congress has sought to understand and address the root causes of these migration trends."
CRS In Focus, IF11151
Congressional Research Service: https://crsreports.congress.gov/