-97.51% is the change from 842 to 21
Calculation steps:
[( 21 - 842 ) ÷ 842] x 100 = -97.51%
Formula
Percentage change = [(21 - 842) / 842] x 100
Subtract the new number by the original number
21 - 842 = -821
-821 ÷ 842 = -0.9750593824228029
-0.9750593824228029 x 100 = -97.51%