CREATE TABLE table_14641 ("Institution" TEXT, "Location" TEXT, "Nickname" TEXT, "Founded" FLOAT, "Type" TEXT, "Enrollment" FLOAT, "Joined" FLOAT)

Name the average founded with joined less than 2008
SELECT AVG("Founded") FROM table_14641 WHERE "Joined" < '2008'
SELECT AVG("Founded") FROM "table_14641" WHERE "Joined" < '2008'