How many mens doubles when womens doubles is catrine bengtsson margit borg?
CREATE TABLE table_17517 (
    "Year" real,
    "Mens singles" text,
    "Womens singles" text,
    "Mens doubles" text,
    "Womens doubles" text,
    "Mixed doubles" text
)
SELECT COUNT("Mens doubles") FROM table_17517 WHERE "Womens doubles" = 'Catrine Bengtsson Margit Borg'
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 mens doubles when womens doubles is catrine bengtsson margit borg? ### Input: CREATE TABLE table_17517 (
    "Year" real,
    "Mens singles" text,
    "Womens singles" text,
    "Mens doubles" text,
    "Womens doubles" text,
    "Mixed doubles" text
) ### Response: SELECT COUNT("Mens doubles") FROM table_17517 WHERE "Womens doubles" = 'Catrine Bengtsson Margit Borg'