user: Question: What's the average year for the name aida-wedo dorsa with a diameter less than 450?
Columns: ['Name', 'Latitude', 'Longitude', 'Diameter (km)', 'Year named']
Types: ['text', 'text', 'text', 'real', 'real']
Sample row: ['Abe Mango Dorsa', '47.0N', '212.0E', 800.0, 1997.0]
SQL:

assistant: SELECT AVG("Year named") FROM "Table" WHERE "Name" = 'aida-wedo dorsa' AND "Diameter (km)" < 450.0;