The population went from 83927 to 135163 over a ten year period What is the percent increase?

increase = (new - old) ÷ old x 100%

= (135163 - 83927) ÷ 83927 x 100%

= 51236 ÷ 83927 x 100%

≈ 0.61 x 100%

= 61%