How many values of r z (arcsecond) correspond with a r y (arcsecond) value of 0.247?
CREATE TABLE table_15318324_1 (
    r_z___arcsecond__ VARCHAR,
    r_y___arcsecond__ VARCHAR
)
SELECT r_z___arcsecond__ FROM table_15318324_1 WHERE r_y___arcsecond__ = "−0.247"
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 values of r z (arcsecond) correspond with a r y (arcsecond) value of 0.247? ### Input: CREATE TABLE table_15318324_1 (
    r_z___arcsecond__ VARCHAR,
    r_y___arcsecond__ VARCHAR
) ### Response: SELECT r_z___arcsecond__ FROM table_15318324_1 WHERE r_y___arcsecond__ = "−0.247"