-11.61% is the change from 939 to 830
Calculation steps:
[( 830 - 939 ) ÷ 939] x 100 = -11.61%
Formula
Percentage change = [(830 - 939) / 939] x 100
Subtract the new number by the original number
830 - 939 = -109
-109 ÷ 939 = -0.11608093716719915
-0.11608093716719915 x 100 = -11.61%