user: Question: What year(s) was Duisburg runner-up?
Columns: ['Team', 'Winners', 'Runners-up', 'Years won', 'Years runner-up']
Types: ['text', 'real', 'real', 'text', 'text']
Sample row: ['Hamburg', 2.0, 1.0, '2005 , 2007', '1999']
SQL:

assistant: SELECT "Years runner-up" FROM "Table" WHERE "Team" = 'Duisburg';