CREATE TABLE table_31329 ("Episode" FLOAT, "Date" TEXT, "Official rating 4+" TEXT, "Share 4+" TEXT, "Official rating 16-39" TEXT, "Share 16-39" TEXT)

What was the official rating 16-39 of episode 9?
SELECT "Official rating 16-39" FROM table_31329 WHERE "Episode" = '9'
SELECT "Official rating 16-39" FROM "table_31329" WHERE "Episode" = '9'