-61.74% is the change from 839 to 321
Calculation steps:
[( 321 - 839 ) ÷ 839] x 100 = -61.74%
Formula
Percentage change = [(321 - 839) / 839] x 100
Subtract the new number by the original number
321 - 839 = -518
-518 ÷ 839 = -0.6174016686531585
-0.6174016686531585 x 100 = -61.74%