CREATE TABLE table_21813 ("Season" TEXT, "Timeslot" TEXT, "Premiere" TEXT, "Finale" TEXT, "TV season" TEXT, "Ranking" TEXT, "Viewers  ( in millions ) " TEXT)

What is every value for viewers for ranking #51 for the Tuesday 9:00 p.m. timeslot?
SELECT "Viewers (in millions)" FROM table_21813 WHERE "Ranking" = '#51' AND "Timeslot" = 'Tuesday 9:00 p.m.'
SELECT "Viewers (in millions)" FROM "table_21813" WHERE "Ranking" = '#51' AND "Timeslot" = 'Tuesday 9:00 p.m.'