user: Question: What is the least year when men's singles is Raju Rai?
Columns: ['Year', 'Mens Singles', 'Womens Singles', 'Mens Doubles', 'Womens Doubles', 'A Mixed Doubles', 'B Mixed Doubles']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1997.0, 'Chibing Wu', 'Vivian Tam', 'Tomasz Malcharek Chibing Wu', 'Charlotte Ackerman Liz Wilson', 'Chibing Wu Alison Brown', 'Not held']
SQL:

assistant: SELECT MIN("Year") FROM "Table" WHERE "Mens Singles" = 'Raju Rai';