-27.25% is the change from 921 to 670
Calculation steps:
[( 670 - 921 ) ÷ 921] x 100 = -27.25%
Formula
Percentage change = [(670 - 921) / 921] x 100
Subtract the new number by the original number
670 - 921 = -251
-251 ÷ 921 = -0.2725298588490771
-0.2725298588490771 x 100 = -27.25%