CREATE TABLE table_22209 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( millions ) " TEXT)

How many series had viewers totaling 23.93 million?
SELECT COUNT("Series #") FROM table_22209 WHERE "U.S. viewers (millions)" = '23.93'
SELECT COUNT("Series #") FROM "table_22209" WHERE "U.S. viewers (millions)" = '23.93'