-79.5% is the change from 839 to 172
Calculation steps:
[( 172 - 839 ) ÷ 839] x 100 = -79.5%
Formula
Percentage change = [(172 - 839) / 839] x 100
Subtract the new number by the original number
172 - 839 = -667
-667 ÷ 839 = -0.7949940405244339
-0.7949940405244339 x 100 = -79.5%