-27.69% is the change from 921 to 666
Calculation steps:
[( 666 - 921 ) ÷ 921] x 100 = -27.69%
Formula
Percentage change = [(666 - 921) / 921] x 100
Subtract the new number by the original number
666 - 921 = -255
-255 ÷ 921 = -0.2768729641693811
-0.2768729641693811 x 100 = -27.69%