-62.4% is the change from 851 to 320
Calculation steps:
[( 320 - 851 ) ÷ 851] x 100 = -62.4%
Formula
Percentage change = [(320 - 851) / 851] x 100
Subtract the new number by the original number
320 - 851 = -531
-531 ÷ 851 = -0.6239717978848414
-0.6239717978848414 x 100 = -62.4%