let's say that the current population is x. The question is then when will it be 5x?
let's see:
after the first year it will be 1.32x
after the second year it will be 1.32(1.32x) =1.74x
after the third year it will be 1.32(1.32(1.32x)) =2,29x
after the forth year it will be 1.32(1.32(1.32(1.32x)))=3x
after the firth year it will be 1.32(1.32(1.32(1.32(1.32x))))=4x
after the sith year it will be 1.32(1.32(1.32(1.32(1.32(1.32x)))))=5,28x
so the answer is : after 6 years.