How many times did outgoing manager Bart de Roover vacated a position?
CREATE TABLE table_29458 (
    "Team" text,
    "Outgoing manager" text,
    "Manner of departure" text,
    "Date of vacancy" text,
    "Replaced by" text,
    "Date of appointment" text,
    "Position in table" text
)
SELECT COUNT("Date of vacancy") FROM table_29458 WHERE "Outgoing manager" = 'Bart De Roover'
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 times did outgoing manager Bart de Roover vacated a position? ### Input: CREATE TABLE table_29458 (
    "Team" text,
    "Outgoing manager" text,
    "Manner of departure" text,
    "Date of vacancy" text,
    "Replaced by" text,
    "Date of appointment" text,
    "Position in table" text
) ### Response: SELECT COUNT("Date of vacancy") FROM table_29458 WHERE "Outgoing manager" = 'Bart De Roover'