CREATE TABLE table_28395 ("Institution" TEXT, "Location" TEXT, "Nickname" TEXT, "Founded" FLOAT, "Type" TEXT, "Enrollment" FLOAT, "Joined MAC" FLOAT)

What is the highest enrollment schools that joined the mac in 1997?
SELECT MAX("Enrollment") FROM table_28395 WHERE "Joined MAC" = '1997'
SELECT MAX("Enrollment") FROM "table_28395" WHERE "Joined MAC" = '1997'