`.  According to the Airliners.net description of the CRJ-100 and 200, ``The original CRJ-100 series - the 100, 100ER and 100LR - was augmented by the 200 series (with more efficient engines) in 1995.``  This particular aircraft was manufactured six years after the switchover.  The confusion is because this flight was usually operated by a CRJ-100, but since seating is the same they can often be substituted for one another`