CREATE TABLE Addresses (state_province_county VARCHAR(255), address_id VARCHAR(255)); CREATE TABLE Staff (staff_address_id VARCHAR(255))
List the states which have between 2 to 4 staffs living there.
    
SQL: SELECT T1.state_province_county FROM Addresses AS T1 JOIN Staff AS T2 ON T1.address_id = T2.staff_address_id GROUP BY T1.state_province_county HAVING COUNT(*) BETWEEN 2 AND 4