Bihar received lots of new trains when the railway min was from the region. Subsequently when Mamata Banerjee was the rail minister, yet again they continued to get benefit of trains going from Eastern/North eastern states which were going to Delhi. So probably in the last decade or so ,I feel this is probably one of the few 1-2 states to have got maximum trains.
Unfortunately, the infrastructure was never improved, extra lines were not added & I guess this could have resulted in the current state