-20.26% is the change from 839 to 669
Calculation steps:
[( 669 - 839 ) ÷ 839] x 100 = -20.26%
Formula
Percentage change = [(669 - 839) / 839] x 100
Subtract the new number by the original number
669 - 839 = -170
-170 ÷ 839 = -0.2026221692491061
-0.2026221692491061 x 100 = -20.26%