-28.01% is the change from 921 to 663
Calculation steps:
[( 663 - 921 ) ÷ 921] x 100 = -28.01%
Formula
Percentage change = [(663 - 921) / 921] x 100
Subtract the new number by the original number
663 - 921 = -258
-258 ÷ 921 = -0.28013029315960913
-0.28013029315960913 x 100 = -28.01%