how many times was a conference held in san francisco ?
CREATE TABLE table_204_15 (
    id number,
    "year" number,
    "date" text,
    "venue" text,
    "city" text,
    "country" text,
    "notes" text
)
SELECT COUNT(*) FROM table_204_15 WHERE "city" = 'san francisco'
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 a conference held in san francisco ? ### Input: CREATE TABLE table_204_15 (
    id number,
    "year" number,
    "date" text,
    "venue" text,
    "city" text,
    "country" text,
    "notes" text
) ### Response: SELECT COUNT(*) FROM table_204_15 WHERE "city" = 'san francisco'