How many episodes aired on October 17, 2007?
CREATE TABLE table_27191 (
    "#" real,
    "Episode" text,
    "Air Date" text,
    "Timeslot (EST)" text,
    "Rating" text,
    "Share" real,
    "18-49 (Rating/Share)" text,
    "Viewers (m)" text,
    "Weekly Rank (#)" real
)
SELECT COUNT("Episode") FROM table_27191 WHERE "Air Date" = 'October 17, 2007'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How many episodes aired on October 17, 2007? ### Input: CREATE TABLE table_27191 (
    "#" real,
    "Episode" text,
    "Air Date" text,
    "Timeslot (EST)" text,
    "Rating" text,
    "Share" real,
    "18-49 (Rating/Share)" text,
    "Viewers (m)" text,
    "Weekly Rank (#)" real
) ### Response: SELECT COUNT("Episode") FROM table_27191 WHERE "Air Date" = 'October 17, 2007'