There were 3 flights in JIMENA of 1991 - the 23I, 23H and 24I flights. However,
there were altitude changes during the first 2 flights: the first 2
penetrations of the 23I flight were at 850 mb, and the next 5 were at 700mb;
the first 2 penetrations of the 23H flight were at 700 mb and the final two
were at 600 mb. These two flights had to be divided into two logical flights
each, giving a total of 5 logical flights for the storm.