Explanation:
percent change = (new value - old value) / old value x 100%
Where the old value is the population in 2000 and the new value is the population in 2010.
percent change = (28000 - 19500) / 19500 x 100%
percent change = 8500 / 19500 x 100%
percent change = 0.435 x 100%
percent change = 43.5%
Therefore, the percent of change in population from 2000 to 2010 is 43.5%.