Energy efficiencies

You will write functions for the three efficiencies of an animal and for the ecological efficiency between two trophic levels.

The idea. $\text{assimilated} = \text{ingested} - \text{egested}$. The new tissue is the assimilated energy minus the respired energy. Each efficiency is a ratio, given in per cent.

Your tasks.

1. Finish assimilation_efficiency. It uses the energy ingested and the energy egested.
2. Finish net_production_efficiency. It uses the energy ingested, egested and respired.
3. Finish ecological_efficiency. It uses the production of an upper level and of the level below.