-97.7% is the change from 871 to 20
Calculation steps:
[( 20 - 871 ) ÷ 871] x 100 = -97.7%
Formula
Percentage change = [(20 - 871) / 871] x 100
Subtract the new number by the original number
20 - 871 = -851
-851 ÷ 871 = -0.9770378874856487
-0.9770378874856487 x 100 = -97.7%