CREATE TABLE table_2577 ("No. in series" TEXT, "No. in season" TEXT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( millions ) " TEXT)

How many times was u.s. Viewers listed for episode 36 in the series?
SELECT COUNT("U.S. viewers (millions)") FROM table_2577 WHERE "No. in series" = '36'
SELECT COUNT("U.S. viewers (millions)") FROM "table_2577" WHERE "No. in series" = '36'