Name the slope length for 1966 groundstation
CREATE TABLE table_17814458_1 (
    slope_length VARCHAR,
    elevation_groundstation VARCHAR
)
SELECT COUNT(slope_length) FROM table_17814458_1 WHERE elevation_groundstation = 1966
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: Name the slope length for 1966 groundstation ### Input: CREATE TABLE table_17814458_1 (
    slope_length VARCHAR,
    elevation_groundstation VARCHAR
) ### Response: SELECT COUNT(slope_length) FROM table_17814458_1 WHERE elevation_groundstation = 1966