-79.62% is the change from 839 to 171
Calculation steps:
[( 171 - 839 ) ÷ 839] x 100 = -79.62%
Formula
Percentage change = [(171 - 839) / 839] x 100
Subtract the new number by the original number
171 - 839 = -668
-668 ÷ 839 = -0.7961859356376639
-0.7961859356376639 x 100 = -79.62%