The Border Patrol made 310,531 arrests during the fiscal year that ended Sept. 30, a decline of 25 percent from 415,816 a year earlier and the lowest level since 1971. Despite the significant decline, arrests increased every month since May — largely families and unaccompanied children.

Immigration and Customs Enforcement, whose officers pick up people for deportation away from the border, made 143,470 arrests, an increase of 25 percent from 114,434 a year earlier. After Trump took office, ICE arrests surged 40 percent from the same period a year earlier.