World population was 6.13 billion in 2000 and was 7.32 billion in 2015, which means the population grew, on average, by 0.079 billion people per year during that time. The percent rate of growth of the population is declining, but the absolute rate is increasing. At the start of 2000, the population was growing by 0.076 billion people per year, while at the start of 2015, it was growing by 0.082 billion people per year. Is each of the numbers
(i) An average rate of change, 

(ii) An instantaneous rate of change, or 

(iii) Not a rate of change of world population?

(a) 6.13 

(b) 7.32 

(c) 0.079

(d) 0.076 

(e) 0.082