passages.id: split_6_test_1961_passage
passages.type: progene_text
passages.text: Patients were divided into age groups as follows : young infants ( < or = 2 mo ) , older infants ( > 2 mo to < 2 yr ) , young children ( 2 to < 7 yr ) , older children ( 7 to < 13 yr ) , adolescents ( 13 to < 16 yr ) , and young adults ( 16 to < 18 yr ) .