-97.8% is the change from 955 to 21
Calculation steps:
[( 21 - 955 ) ÷ 955] x 100 = -97.8%
Formula
Percentage change = [(21 - 955) / 955] x 100
Subtract the new number by the original number
21 - 955 = -934
-934 ÷ 955 = -0.9780104712041885
-0.9780104712041885 x 100 = -97.8%