user: Question: What year was there No competition in Women's singles?
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: ['1991', 'Arthur Chatschatourow', 'Inga Beridse', 'No competition', 'No competition', 'No competition']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Women's singles" = 'No competition';