how many times was ayrton senna in pole position ?
CREATE TABLE table_204_455 (
    id number,
    "rd." number,
    "grand prix" text,
    "date" text,
    "location" text,
    "pole position" text,
    "fastest lap" text,
    "winning driver" text,
    "constructor" text,
    "report" text
)
SELECT COUNT(*) FROM table_204_455 WHERE "pole position" = 'ayrton senna'
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 times was ayrton senna in pole position ? ### Input: CREATE TABLE table_204_455 (
    id number,
    "rd." number,
    "grand prix" text,
    "date" text,
    "location" text,
    "pole position" text,
    "fastest lap" text,
    "winning driver" text,
    "constructor" text,
    "report" text
) ### Response: SELECT COUNT(*) FROM table_204_455 WHERE "pole position" = 'ayrton senna'