List the states which have between 2 to 4 staffs living there.
create table addresses (state_province_county varchar, address_id varchar, PRIMARY KEY (state_province_county)); create table staff (staff_address_id varchar, PRIMARY KEY (staff_address_id))
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