user: ### NOW ANSWER:
Question: How many years has Sasol Jordan Yamaha as an Entrant?
Columns: ['Year', 'Entrant', 'Chassis', 'Engine', 'Points']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1987.0, 'Motor Racing Developments', 'Brabham BT56', 'BMW Str-4', 0.0]
SQL:

assistant: SELECT AVG("Year") FROM "Table" WHERE "Entrant" = 'Sasol Jordan Yamaha';