-96.42% is the change from 839 to 30
Calculation steps:
[( 30 - 839 ) ÷ 839] x 100 = -96.42%
Formula
Percentage change = [(30 - 839) / 839] x 100
Subtract the new number by the original number
30 - 839 = -809
-809 ÷ 839 = -0.964243146603099
-0.964243146603099 x 100 = -96.42%