user: Question: Tell me the least silver for total less than 6 and rank of 8
Columns: ['Rank', 'Nation', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['text', 'text', 'real', 'real', 'real', 'real']
Sample row: ['1', 'Canada (CAN)', 16.0, 16.0, 11.0, 43.0]
SQL:

assistant: SELECT MIN("Silver") FROM "Table" WHERE "Total" < 6.0 AND "Rank" = '8';