-97.72% is the change from 920 to 21
Calculation steps:
[( 21 - 920 ) ÷ 920] x 100 = -97.72%
Formula
Percentage change = [(21 - 920) / 920] x 100
Subtract the new number by the original number
21 - 920 = -899
-899 ÷ 920 = -0.9771739130434782
-0.9771739130434782 x 100 = -97.72%