What is the qual for rank 18 in 1964?
CREATE TABLE table_15606 (
    "Year" text,
    "Start" text,
    "Qual" text,
    "Rank" text,
    "Finish" text,
    "Laps" real
)
SELECT "Qual" FROM table_15606 WHERE "Rank" = '18' AND "Year" = '1964'
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: What is the qual for rank 18 in 1964? ### Input: CREATE TABLE table_15606 (
    "Year" text,
    "Start" text,
    "Qual" text,
    "Rank" text,
    "Finish" text,
    "Laps" real
) ### Response: SELECT "Qual" FROM table_15606 WHERE "Rank" = '18' AND "Year" = '1964'