IOWA CITY — The University of Iowa is tightening the rules for incoming out-of-state students seeking in-state residency after beginning their studies. Officials say a record 317 part-time freshmen enrolled at the university for fall 2016. Many of those nonresidents weren’t taking enough credit hours to trigger the higher, full-time tuition. Out-of-state students who want to become residents must live in Iowa for at least a 12 months.