On July 17, 2008, what was the total number of lead maragin?
CREATE TABLE table_21046 (
    "Poll Source" text,
    "Dates administered" text,
    "Democrat: Mark Begich" text,
    "Republican: Ted Stevens" text,
    "Lead Maragin" real
)
SELECT COUNT("Lead Maragin") FROM table_21046 WHERE "Dates administered" = 'July 17, 2008'
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: On July 17, 2008, what was the total number of lead maragin? ### Input: CREATE TABLE table_21046 (
    "Poll Source" text,
    "Dates administered" text,
    "Democrat: Mark Begich" text,
    "Republican: Ted Stevens" text,
    "Lead Maragin" real
) ### Response: SELECT COUNT("Lead Maragin") FROM table_21046 WHERE "Dates administered" = 'July 17, 2008'