-81.68% is the change from 939 to 172
Calculation steps:
[( 172 - 939 ) ÷ 939] x 100 = -81.68%
Formula
Percentage change = [(172 - 939) / 939] x 100
Subtract the new number by the original number
172 - 939 = -767
-767 ÷ 939 = -0.8168264110756124
-0.8168264110756124 x 100 = -81.68%