user: Question: What is the year when Conrad Hückstädt won Men's Single?
Columns: ['Year', "Men's singles", "Women's singles", "Men's doubles", "Women's doubles", 'Mixed doubles']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['2000', 'Boris Kessov', 'Petya Nedelcheva', 'Luben Panov Jassen Borissov', 'Petya Nedelcheva Diana Koleva', 'Slantchezar Tzankov Petya Nedelcheva']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Men's singles" = 'Conrad Hückstädt';