Question

Calculate the percentage growth for a county with a population of 6 million in a year in which it had 100,000 births, 70,000 deaths, 30,000 immigrants and 40,000 emigrants

Answer 1

Country's population = 6 million 
The percentage growth rate = (10,000/6,000,000)*100 = 0.166666666667% 

2. Reduction in concentration = 65 ppm - 7 ppm = 58 ppm 
Percentage change = (58 ppm/ 65 ppm)*100 = 89.23%then again i may be wrong