Table: aircraft_inventory
Columns: manufacturer
model
quantity
introduced
retired

Question: How many in the introduced section had Fokker as a manufacturer, a quantity of 5, and retired later than 1999?
SQL: SELECT SUM("introduced") FROM aircraft_inventory WHERE "manufacturer" = 'fokker' AND "quantity" = 5 AND "retired" > 1999

Question: What is the total number of quantity when the introductory year was 1984?
SQL: SELECT SUM("quantity") FROM aircraft_inventory WHERE "introduced" = 1984

Question: How many in the introduced segment retired later than 1994 and had Fokker as a manufacturer?
SQL: SELECT COUNT("introduced") FROM aircraft_inventory WHERE "retired" > 1994 AND "manufacturer" = 'fokker'

Question: How many in the quantity section had Fokker as a manufacturer and retired later than 1999?
SQL: SELECT COUNT("quantity") FROM aircraft_inventory WHERE "manufacturer" = 'fokker' AND "retired" > 1999