Bus

import statistics
import numpy

n = 0
i = 0
a = []

stop1 = (5,0)
stop2 = (4,2)
stop3 = (8,5)
stop4 = (2,2)

stops = [stop1, stop2, stop3, stop4]
l= len(stops)
a = [None] * l

while i < l:
    n = n + stops[i][0] - stops[i][1]
    a[i]= n
    print(n)
    i=i+1


print('The bus stopped', l, 'times, the max number of passengers was:', max(a) ,'the average occupation was ', statistics.mean(a) ,' and the standard deviation was' ,numpy.std(a))