user: ### NOW ANSWER:
Question: How many in the introduced section had fokker as a manufacturer, a quantity of 5, and retired later than 1999?
Columns: ['Manufacturer', 'Model', 'Quantity', 'Introduced', 'Retired']
Types: ['text', 'text', 'real', 'real', 'real']
Sample row: ['Douglas', 'C-54 Skymaster', 6.0, 1947.0, 1966.0]
SQL:

assistant: SELECT SUM("Introduced") FROM "Table" WHERE "Manufacturer" = 'fokker' AND "Quantity" = 5.0 AND "Retired" > 1999.0;