user: Question: What is the average bronze medal when gold is greater than 0, and there is less than 0 silver medals?
Columns: ['Rank', 'Nation', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['real', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Australia (AUS)', 8.0, 4.0, 2.0, 14.0]
SQL:

assistant: SELECT AVG("Bronze") FROM "Table" WHERE "Gold" > 0.0 AND "Silver" < 0.0;