When did the duchess who became duchess on 7/8 April 1766 cease to be duchess?
CREATE TABLE table_37104 (
    "Name" text,
    "Birth" text,
    "Marriage" text,
    "Became Duchess" text,
    "Ceased to be Duchess" text,
    "Death" text,
    "Spouse" text
)
SELECT "Ceased to be Duchess" FROM table_37104 WHERE "Became Duchess" = '7/8 april 1766'
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: When did the duchess who became duchess on 7/8 April 1766 cease to be duchess? ### Input: CREATE TABLE table_37104 (
    "Name" text,
    "Birth" text,
    "Marriage" text,
    "Became Duchess" text,
    "Ceased to be Duchess" text,
    "Death" text,
    "Spouse" text
) ### Response: SELECT "Ceased to be Duchess" FROM table_37104 WHERE "Became Duchess" = '7/8 april 1766'