CREATE TABLE table_28409 ("Institution" TEXT, "Location" TEXT, "Nickname" TEXT, "Founded" FLOAT, "Type" TEXT, "Enrollment" FLOAT, "Football?" TEXT, "Joined" FLOAT)

How many values for joined occur at Guilford College?
SELECT COUNT("Joined") FROM table_28409 WHERE "Institution" = 'Guilford College'
SELECT COUNT("Joined") FROM "table_28409" WHERE "Institution" = 'Guilford College'