-22.88% is the change from 839 to 647
Calculation steps:
[( 647 - 839 ) ÷ 839] x 100 = -22.88%
Formula
Percentage change = [(647 - 839) / 839] x 100
Subtract the new number by the original number
647 - 839 = -192
-192 ÷ 839 = -0.22884386174016685
-0.22884386174016685 x 100 = -22.88%