The population of City A for each of three years is shown in the table above. If the population grew by m percent from 1970 to 1980 and n percent from 1980 to 1990, then m exceeds n by how much?	Choose the most appropriate option:
A) 37.5	B) 20	C) 17.5	D) 15	E) 12.5
70 - 80   m = (55-40)/40 = 3/8   80 - 90   n = (66-55)/55 = 1/5   m - n   3/8 - 1/5 = 7/40 = 17.5%   ANSWER:17.5
<result>C</result>
The population of City A for each of three years is shown in the table above. If the population grew by m percent from 1970 to 1980 and n percent from 1980 to 1990, then m exceeds n by how much?