In 1991 the population of a town was a perfect square. Ten years later, after an increase of 100 people, the population was 4 more than a perfect square. Now, in 2011, with an increase of another 100 people, the population is once again a perfect square. Which of the following is closest to the percent growth of the town's population during this twenty-year period?
33
38
43
48
53
