What is the number of leg for ss17
CREATE TABLE table_622 (
    "Leg" text,
    "Stage" text,
    "Time (EEST)" text,
    "Name" text,
    "Length" text,
    "Winner" text,
    "Time" text,
    "Avg. spd." text,
    "Rally leader" text
)
SELECT COUNT("Leg") FROM table_622 WHERE "Stage" = 'SS17'
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 number of leg for ss17 ### Input: CREATE TABLE table_622 (
    "Leg" text,
    "Stage" text,
    "Time (EEST)" text,
    "Name" text,
    "Length" text,
    "Winner" text,
    "Time" text,
    "Avg. spd." text,
    "Rally leader" text
) ### Response: SELECT COUNT("Leg") FROM table_622 WHERE "Stage" = 'SS17'