Among the employees who are Trainees, how many of them work in New York?
Trainees is a position title; California refers to state = 'NY'
SELECT COUNT(*) FROM employee AS T1  INNER JOIN location AS T2  ON T1.locationID = T2.locationID INNER JOIN position AS T3  ON T3.positionID = T1.positionID WHERE T3.positiontitle = 'Trainee' AND T2.state = 'NY'