CREATE TABLE table_23434 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( millions ) " TEXT)

How many different numbers of people in the US who'd seen the episode with a season number 8 are there?
SELECT COUNT("U.S. viewers (millions)") FROM table_23434 WHERE "No. in season" = '8'
SELECT COUNT("U.S. viewers (millions)") FROM "table_23434" WHERE "No. in season" = '8'