Brain capacity of the human line

You have the NCERT brain capacities of three ancestors as a table of low and high values. You will write three small functions that find the middle of a range, a percentage rise, and the rises between all the steps.

The idea. The middle of a range is the average of its ends. A percentage rise is the increase divided by the earlier value, times 100.

Your tasks.

1. Finish middle. It gives the middle of a range of brain capacity.
2. Finish percent_rise. It gives the percentage rise from before to after.
3. Finish rises. It gives a list with the percentage rise from each step of the table to the next, rounded to one decimal place.