Why do we have a greater number of organisms at lower trophic levels?

We have a greater number of organisms at lower trophic levels in order to provide large amount of energy to the higher trophic levels in the food chain because a very less amount of energy is left as we go towards the higher trophic levels. Most of the energy is lost as a heat to the environment and only 10% energy is transferred to the next trophic level. So a very less amount of energy is left for consumers at higher levels. That is why, lower trophic levels have large number of organisms.