how many ranks are there ?
CREATE TABLE table_204_521 (
    id number,
    "rank" number,
    "name" text,
    "nationality" text,
    "time (hand)" text,
    "notes" text
)
SELECT COUNT("rank") FROM table_204_521
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 ranks are there ? ### Input: CREATE TABLE table_204_521 (
    id number,
    "rank" number,
    "name" text,
    "nationality" text,
    "time (hand)" text,
    "notes" text
) ### Response: SELECT COUNT("rank") FROM table_204_521