Unless you were on a leave of absence or withdrew before the school closed, the last date of attendance should be the same as the date the school closed. (studentloanborrowerassistance.org)
But there's no need to advertise your age by including dates of attendance and / or the year you graduated on your resume. (careerintelligenceresumewriting.com)
Provide the name of each school attended along with dates of attendance and degree or degrees earned. (careertrend.com)