CREATE TABLE table_18762 ("Season" TEXT, "Timeslot" TEXT, "Season Premiere" TEXT, "Season Finale" TEXT, "Episodes" FLOAT, "TV Season" TEXT, "Ranking" TEXT, "Viewers  ( in millions ) " TEXT)

How many rankings did the 5th season have?
SELECT COUNT("Ranking") FROM table_18762 WHERE "Season" = '5th'
SELECT COUNT("Ranking") FROM "table_18762" WHERE "Season" = '5th'