CREATE TABLE table_15118 ("Year" FLOAT, "Division I" TEXT, "Division II" TEXT, "Division III" TEXT, "Division IV" TEXT, "Division V" TEXT)

With a Division II of Portsmouth, what is the Division IV?
SELECT "Division IV" FROM table_15118 WHERE "Division III" = 'portsmouth'
SELECT "Division IV" FROM "table_15118" WHERE "Division III" = 'portsmouth'